Does credit create a ‘growth imperative’? A quasi-stationary economy with interest-bearing debt


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Ecological Economics


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Ecological Economics 120 (2015) 3248






Does credit create a growth imperative? A quasi-stationary economy with  interest-bearing  debt

Tim Jackson a,, Peter A. Victor b

a Centre for the Understanding of Sustainable Prosperity, University of Surrey, Guildford, UK

b Faculty of Environmental Studies, York University, 4700 Keele St, Canada




a r t i c l e          i n f o  


Article history:

Received 11 June 2015

Received in revised form 5 September 2015 Accepted 20 September 2015

Available online 22 October 2015



Growth imperative Credit creation Interest

Money creation

Stock-ow consistent model Austerity


a b s t r a c t  


This paper addresses the question of whether a capitalist economy can ever sustain a stationary (or non- growing) state, or whether, as often claimed, capitalism has an inherent growth imperative arising from the

charging of interest on debt. We outline the development of a dedicated system dynamics macro-economic model for describing Financial Assets and Liabilities in a Stock-Flow consistent Framework (FALSTAFF) and use this model to explore the potential for stationary state outcomes in an economy with balanced trade, credit cre- ation by banks, and private equity. Contrary to claims in the literature, we find that neither credit creation nor the

charging of interest on debt creates a growth imperative in and of themselves. This finding remains true even

when capital adequacy and liquidity requirements are imposed on banks. We test the robustness of our results in the face of random variations and one-off shocks. We show further that it is possible to move from a growth path towards a stationary state without either crashing the economy or dismantling the system. Nonetheless, there remain several good reasons to support the reform of the monetary system. Our model also supports cri- tiques of austerity and underlines the value of countercyclical spending by government.

© 2015 Elsevier B.V. All rights reserved.





1. Introduction


It has been argued that capitalism has an inherent ‘growth impera- tive’: in other words, that there are certain  features  of  capitalism which are inimical to a stationary state1  of the real economy. This argu-

ment has its roots in the writings of Marx (1867) and Rosa Luxemburg (1913) and there are good reasons to take it seriously. For instance, under certain conditions, the desire of entrepreneurs to maximise profits will lead to the pursuit of labour productivity gains in produc- tion. Unless the economy grows over time, aggregate labour demand

will fall, leading to a ‘productivity trap’ (Jackson and Victor, 2011) in

which higher and higher levels of unemployment can only be offset by continued economic growth.


*  Corresponding author.

E-mail address: (T. Jackson).

1 We use the term stationary state to describe zero growth in the Gross Domestic Product (GDP). We prefer here stationary to steady state, which is also widely used else- where to refer to a non-growing economy (Daly, 2014 eg), for several reasons. First, the

term steady state is employed in the post-Keynesian literature to describe a state of the economy in which the key variables remain in a constant relationship to each other (Godley and Lavoie, 2007:71) but this may still entail growth. A stationary state is used to describe a state in which both flows and stocks are constant, in which case there is no

growth. Second, the terminology of the stationary stateharks back to early classical

economists such as Mill (1848), emphasising the pedigree behind the idea of a non- growth-based economy. Finally, as one of our reviewers pointed out, the term steady state growth was commonly found in the literature (Hahn and Matthews, 1964: 781; Solow, 1970: Ch 1) prior to Daly's concept of a steady state economy.


Our concern in this paper is to address one particular aspect of the growth imperative: namely, the question of interest-bearing debt. A va- riety of authors have suggested that when money is created in parallel with interest-bearing debt it inevitably creates a growth imperative. To some, the charging of interest on debt is itself an underlying driver for economic growth. In the absence of growth, it is argued, it would be impossible to service interest payments and repay debts, which would therefore accumulate unsustainably. This claim was made, for in- stance, by Richard Douthwaite (1990, 2006). In The Ecology of Money,

Douthwaite (2006) suggests that the ‘fundamental problem with the

debt method of creating money is that, because interest has to be paid on almost all of it, the economy must grow continuously if it is not to collapse.’

This view has been influential amongst a range of economists critical of capitalism, and in particular those critical of the system of creation of money through interest-bearing debt. Eisenstein (2012) maintains that

‘our present money system can only function in a growing economy.

Money is created as interest-bearing debt: it only comes into being when someone promises to pay back even more of it’. In a similar vein, Farley et al. (2013) claim that the ‘current interest-bearing, debt- based system of money creation stimulates the unsustainable growth economy’ (op cit: 2803). The same authors seek to identify policies that ‘would limit the growth imperative created by an interest-based credit creation system’ (op cit: 2823).

The popular understanding that debt-based money is a form of growth imperative is intuitively appealing, but has been subject to

0921-8009/© 2015 Elsevier B.V. All rights reserved.




remarkably little in-depth economic scrutiny. A notableexceptionis a 2009 paper by Mathias Binswanger which sets out to provide an ‘expla- nation for  a  growth  imperative in modern  capitalist  economies,  which are also credit money economies’ (op cit: 707). As a result of the ability of commercial banks to create money through the expansion of credit, he claims (op cit: 724), ‘a zero growth rate is not feasible in the long run’. Binswanger  (2009)  finds  that  much  depends  on  the  destination  of

interest payments in the economy. If banks distribute all their profits (the difference between interest received and interest paid out) to households, then the ‘positive threshold level’ for growth can fall to zero. This condition is ruled out in his analysis, however, by the de-

mands of ‘capital adequacy’— the need to ensure a certain buffer against

risky assets on the balance sheet of commercial banks. This require- ment, underlined by many in the wake of the financial crisis (BIS, 2011) seeks to ensure that banks have sufficient capital to cover the

risk associated with certain kinds of assets (primarily loans). Binswang- er maintains that this requirement is ‘crucial for establishing the growth imperative’ (op cit: 713). By his own admission, however, Binswanger's paper ‘does not aim to give a full description of a modern capitalist econ- omy’. In particular, he notes (op cit: 711) that his model ‘should be dis- tinguished from some recent modelling attempts in the Post Keynesian tradition’ which set out to provide ‘comprehensive, fully articulated, theoretical models’ that could serve as a ‘blueprint for an empirical rep- resentation of a whole economic system’ (Godley, 1999: 394). A recent symposium on the growth imperative has contributed several new

perspectives on Binswanger's original hypothesis, but these papers also fall short of providing a full analysis of this kind (Binswanger, 2015; Rosenbaum, 2015).

In the current paper, we seek to address this limitation. Specifically, we aim to analyse the hypothesis that debt-based money creates a ‘growth imperative’ within a Stock-Flow Consistent (SFC) representa-

tion of the macro-economy. In the following section, we provide a brief overview of a systems dynamic model of the macro-economy, in- cluding both the real and the financial economy and describe the cali- bration of this model with empirically plausible data. Our principal aim is to test the ability of the model to provide for a stationary state. We also explore the stability of the model under one-off shocks and ran- dom fluctuations in consumer demand, and under different responses from government and commercial firms. Finally, we test the potential for transitions from growth states of the economy into stationary states and discuss the implications of these findings for capitalism and for the

‘growth imperative’.


2. Overview of the FALSTAFF Model


The analysis in this paper is based on our development (over the last four years) of a consistent approach to ‘ecological macroeconomics’. Our broad approach draws together three primary spheres of modelling in- terest and explores the interactions between them. These spheres are:

1)  the environmental and resource constraints on economic activity;

2) a full account of production, consumption, employment and public fi- nances in the ‘real economy’ at the level of the nation state; and 3) a comprehensive account of the financial economy, including the main interactions between financial agents, and the creation, flow and de-

struction of the money supply itself. Interactions within and between these spheres of interest are modelled using a system dynamics framework.

An important intellectual foundation for our work comes from the insights of post-Keynesian economics, and in particular from an ap- proach known as Stock-Flow Consistent (SFC) macro-economics, pioneered by Copeland (1949) and developed extensively by the late Wynne Godley and his colleagues.2  SFC modelling has come to the


fore in the wake of the financial crisis, because of the consistency of its accounting principles and the transparency these principles bring not just to an understanding of conventional macroeconomic aggregates like the GDP but also to the underlying financial flows and balance sheets. It is notable that Godley (1999) was one of the few economists who predicted the crisis before it happened.

The overall rationale of the SFC approach is to account consistently for all monetary flows between different sectors across the economy. This rationale can be captured in three broad axioms: first that each ex- penditure from a given actor (or sector) is also the income to another actor (or sector); second, that each sector's financial asset corresponds to some financial liability for at least one other sector, with the sum of all assets and liabilities across all sectors equalling zero; and finally, that changes in stocks of financial assets are consistently related to flows within and between economic sectors. These simple understand- ings lead to a set of accounting principles with implications for actors in both the real and financial economy which can be used to test the con- sistency of economic models and scenario predictions.

Building on these foundations we have developed a macroeconomic model of Financial Assets and Liabilities in a Stock and Flow consistent Framework (FALSTAFF), calibrated at the level of the national economy. The approach is broadly post-Keynesian in the sense that the model is demand-driven and incorporates a consistent account of all monetary flows. The full FALSTAFF model (Jackson et al 2015) is articulated in terms of six inter-related financial sector accounts: households, firms,

banks, government, central bank and the ‘rest of the world’ (foreign sec-

tor). The accounts of firms and banks are further subdivided into current and capital accounts in line with national accounting practises. The household sector can be further subdivided into two sectors in order to test the distributional aspects of changes in the real or financial economy.3

The FALSTAFF model is built using the system dynamics software STELLA. This kind of software provides a useful platform for exploring economic systems for several reasons, not the least of which is the ease of undertaking collaborative, interactive work in a visual (icono- graphic) environment. Further advantages are the transparency with which one can model fully dynamic relationships and mirror the stock-flow consistency that underlies our approach to macroeconomic modelling. STELLA also allows for an online user-interface (NETSIM) through which the interested reader can follow the scenarios presented in this paper and explore their own.4 Data collation and reporting are carried out in Excel.

For the purposes of this paper, we have simplified the FALSTAFF structure in order to focus specifically on the question of interest- bearing money. For instance, we assume balanced trade in this version of FALSTAFF and restrict the number of categories of assets and liabili- ties to include only loans, deposits, equities and government bonds. Fur- ther simplifications are noted at the relevant places in our full model description below. Fig. 1 illustrates the top-level structure of financial flows for the simplified version of FALSTAFF described in this paper.

The familiar ‘circular flow’ of the economy is visible (in red) towards

the bottom of the diagram in Fig. 1. The rather more complex surround- ing structure represents financial flows of the monetary economy in the banking, government and foreign sectors. If the model is stock-flow consistent, the financial flows into and out of each financial sector con- sistently sum to zero throughout the model run. So, for instance, the in- comes of households (consisting of wages, dividends and interest receipts) must be exactly equal to the outgoings of households (includ- ing consumption, taxes, interest payments and net acquisitions of finan- cial assets). Likewise, for each other sector in the model. These balances provide a ready test of consistency in the model.





2 See for instance: Godley, 1999, Godley and Lavoie, 2007, Lavoie and Godley, 2001. For an overview of the literature on SFC macroeconomic modelling, see Caverzasi and Godin, 2015.


We have used this subdivision to explore the implications of Piketty's (2014) hypoth- esis that inequality increases as the growth rate declines (Jackson and Victor, 2015).

4    The online model may be found at:




Fig. 1. An overview of the FALSTAFF stationary state model.



The broad structure of the FALSTAFF model is as follows. Aggregate demand is composed of household spending, government spending, and the investment expenditure of firms.5 The allocation of gross in- come is split between the depreciation of fixed capital (which is as- sumed to be retained by firms), the return to labour (the wage bill) and the return to capital (profits, dividends and interest payments).

Households' propensity to consume is dependent both on income and on financial wealth (Godley and Lavoie, 2007). The model also in- corporates the possibility of exploring two kinds of exogenous ‘shocks’

to household spending. In the first, a random adjustment is made to household spending throughout the run, within a range of plus or minus 2.5% from the predicted value. In the second, a one-off shock ei- ther reduces or increases spending by 5% over two consecutive periods early in the run. We use these exogenous shocks to test the stability of the stationary state under our default assumptions.

Household saving may in principle be distributed between govern- ment bonds, firms equities, banks equities, bank deposits and loans.6 Household demand for bonds is assumed here to be equal to the excess supply of bonds from government, once banks' demands for bonds are met. Household demand for equities is assumed to be equal to the


5  For simplicity, we assume for the purposes of this paper a balanced trade position in which exports are equal to imports and net trade is zero.

In the full FALSTAFF framework, household saving is allocated between a range of fi-


issuance of equities from firms and banks. Thus, households are the sole owners of equity in this model and the return on equities is limited to dividends received, since there are no capital gains in the model.7 The balance of household saving, once bond and equity purchases have been made, is allocated to paying down loans or building up deposits. If saving is negative, households may also increase the level of loans.

Firms are assumed to produce goods and services on demand for households, governments and gross fixed capital investment. Invest- ment decisions are based on a simple accelerator function (Jorgenson, 1963, Godley and Lavoie, 2007) in which net investment is assumed to be a fixed proportion of the difference between capital stock in the previous period, and a target capital stock determined by expected de- mand and an assumed capital-to-output ratio. A proportion of gross profits equal to the depreciation of the capital stock over the previous period is assumed to be retained by firms for investment, with net (ad- ditional) investment financed through a mixture of new loans from banks and the issuance of equities to households, according to a desired debt-to-equity ratio.

Government receives income from taxation and purchases goods and services (for the benefit of the public) from the firms sector. Taxa- tion is only levied on households in this version of the model, at a rate which provides for an initially balanced budget under the default values for aggregate demand. For the purposes of this paper, we explore three


nancial assets (and liabilities) including bank deposits, equities, pension funds, govern-                                      


ment bonds (and mortgage and loans), using an econometrically-estimated portfolio allocation model based on the framework originally proposed by Brainard and Tobin (1968).


7 This assumption is relaxed in the full FALSTAFF model, in which both equity prices and housing vary according to supply and demand. These assets are therefore subject to capital gains in the full model.




government spending scenarios: one in which government spending remains constant throughout the run, one in which government spend- ing plus bond interest is equal to tax receipts (i.e., an ‘austerity’ policy in which government balances the fiscal budget), and one in which gov-

ernment engages in a ‘countercyclical’ spending policy, increasing

spending when aggregate demand falls and decreasing it when aggre- gate demand rises. Government bonds are issued to cover deficit spending.

Banks accept deposits and provide loans to households and to firms, as demanded. Bank profits are generated from the interest rate spread between deposits and loans, plus interest paid on any government bonds they hold. Profits are distributed to households as dividends, ex-

cept for any retained earnings that may be required to meet the capital account ‘financing requirement’. This financing requirement is the dif- ference between deposits (inflows into the capital account) and the sum of loans, bond purchases and increases in central bank reserves (outgoings from the capital account). The central bank plays a very sim-

ple role in the stationary state version of FALSTAFF, providing liquidity on demand (in theformof centralbank reserves) to commercial banks in exchange for government bonds.

FALSTAFF provides for two regulatory policies that might reasonably be imposed on banks. First, the model can impose a ‘capital adequacy’ requirement in which banks are required to hold enough ‘capital’ to cover a given proportion of risky assets. Second, banks may be subject to a central bank ‘reserve ratio’ in which reserves are held at the central

bank up to a given proportion of deposits held on account. Some devel- oped countries (including the UK and Canada) no longer retain formal reserve ratios, leaving it up to the banks themselves to decide what re- serves to hold. However, we have included a default reserve ratio of 5% in order to test Binswanger's hypothesis that such requirements might lead to a growth imperative.

The capital adequacy requirement is supposed to provide resil- ience in the face of defaulting loans, as required for instance under the Basel III framework (BIS, 2011). In fact, we adopt as our starting

point the Basel III requirement that banks' ‘capital’ (the book value

of equity in the banks' balance sheet) should be equal to 8% of risk- weighted assets (loans to households and firms). To meet this re- quirement, banks in FALSTAFF issue equities to households. This has the effect of shifting deposits to equity on the liability side of the balance sheet and increasing the ratio of capital to loans. To bal- ance the balance sheet, banks purchase government bonds (conven- tionally deemed risk-free)   which together with central bank

reserves (also risk-free) provide for a certain proportion of ‘safe’ cap-

ital to balance against risky assets.

Our principal aim in this paper is to identify the potential for a sta- tionary state economy, even in the presence of debt-based money. In fact, it may be noted that our economy is almost entirely a credit money economy. No physical cash changes hands, and transactions are all deemed to be electronic transactions through the bank accounts of firms, household and government (and through the reserve account of the central bank). For the purposes of testing the role of credit crea- tion in the growth imperative, this simplification is clearly robust. We have also incorporated conditions on commercial banks appropriate for the testing of the overall hypothesis that interest-bearing debt leads to growth.





Though central to the real economy, and in particular the envi- ronmental impacts of production and consumption, we are less in-



be set exogenously in the model. The wage rate is assumed to follow any increase in labour productivity.8

Table 1 shows the financial balance sheet for the FALSTAFF ‘steady state’ model. As mentioned above, we have employed a rather simple

asset and liability structure for the purposes of this exercise in order to allow us to focus our attention on the question of interest-bearing debt. Households own firm equities Ef and purchase government bonds Bh. Balances are held either as deposits Dh or as loans Lh. Firms take out loans Lf or issue equities Ef in order to finance investment. Firms' surpluses can either be used to pay down loans or to increase firms deposits Df. In addition to the loans they provide to firms and households, commercial banks also hold government bonds Bb for cap- ital adequacy reasons and central bank reserves R for liquidity reasons. The central bank balances its reserve liabilities with government bonds Bcb purchased from banks on the secondary market. Govern- ments hold only liabilities in the form of bonds B.

The transaction flows matrix (eg Godley and Lavoie, 2007: 39) for FALSTAFF (Table 2) incorporates an account of the incomes and expen- ditures in the national economy, reflecting directly the structure of the system of national accounts. Thus, the first ten rows in Table 2 illustrate the flow accounts of each sector. For instance, the household sector re- ceives money in the form of wages and dividends from production firms and dividends and (net) interest from banks. Households spend money on consumption and on taxes. The balance between income and spend- ing represents the saving of the household sector. Note that the top rows of column 2 (firms' current account) represent a simplified form of the conventional GDP accounting identity:


C þ G þ I ¼ GDPe  ¼ GDPi  ¼ W þ P f  þ i f  þ δ                                               ð1Þ


where GDPe represents the expenditure-based formulation of the GDP, GDPi represents the income based formulation, and if represents the net interest paid out by firms.

The bottom five rows of the table represent the transactions in finan- cial assets and liabilities between sectors. So, for example, the net lend- ing of the households sector (the sum of rows 1 to 10) is distributed amongst five different kinds of financial assets in this illustration: de- posits, loans, government bonds, equities and central bank reserves. A key feature of the transaction matrix, indeed the core principle at the heart of SFC modelling, is that each of the rows and each of the columns must always sum to zero. If the model is correctly constructed, these zero balances should not change over time as the simulation progress. The accounting identities shown in Table 2 therefore allow for a consis- tency check, to ensure that the simulations actually represent possible states of the monetary economy.9


3. Analysis


The aim of this paper is to explore the hypothesis that the creation of money through interest-bearing debt necessarily creates a ‘growth im- perative’. The existence of one reasonable stationary state solution,

based on reasonable and consistent values for the various parameters would disprove the hypothesis. In pursuit of such a solution, we first run through the algebraic structure of the model.

Starting with the household sector, we can define the income Yh, of

households (in accordance with Table 2) as:


terested in this paper in the precise nature ofthe production process itself. Clearly, however, some aspects are important for our task. For instance, we need to establish the capital investment


Yh ¼ W þ Pfd þ  bd


þ iBh  þ iDh iLh                                                                                                                                ð2Þ


needs for production, since these are a core component of aggregate                                     


demand and determine both the level of financing for firms and the destination of household saving. The second major input to produc- tion is labour. Employment in FALSTAFF is assumed to take place via the firms sector and labour demand is calculated through a sim- ple labour productivity equation. Labour productivity growth can


The full version of FALSTAFF includes a model of wage bargaining and therefore allows us to consider the question of prices and inflation.

9    These identities are established in FALSTAFF via the accounting structure shown in Fig.

Error! Reference source not found., in such a manner that the stock associated with each monetary sector must always be empty. This structure therefore provides for a ready visu- al check on the consistency of the model.



Table 1

Financial balance sheet for the FALSTAFF stationary state economy.






Central bank



Net financial worth

Dh + E + Bh Lh

Lf Ef + Df

L + R + Bb D Eb

Bcb R



Financial Assets

Dh + E + Bh


L + R



R + D + L + B + E

Reserves Deposits









Loans Bonds











Financial Liabilities




Lf + Ef


D + Eb






R + D + L + B + E








Deposits Loans



















Our presentation of the financial balance sheet in Table 1 follows the format established in the National Accounts ( eg) rath- er than the presentation favoured by SFC theory (Godley and Lavoie, 2007: 32 eg). A numerical example of the financial balance sheet for FALSTAFF representing the initial state of the model is shown at Appendix 2.









where iBh = rBBh  is the interest paid on the stock of bonds held by





Remembering that households are the only owners of equity in this



households, iDh = rDD1 is the interest paid on households deposits





and iLh = rLLh   the interest paid by households on loans. Disposable in-



model, the household net worth NW


is equal (see Table 1) to:


come, Yhd, is given by:


Yhd   ¼ ð1−θÞYh                                                                                                                                                                                              ð3Þ


where θ is the rate of income tax on households, determined (below) by government's initial financing requirement. In allocating household income between consumption spending, C and saving Sh,

we adopt a consumption function of the form (Godley and Lavoie,


NWh  ¼ Dh þ Bh  þ ELh :                                                                                ð6Þ


Household saving is then given by:


S¼ YhdC:                                                                                                   ð7Þ


In this version of FALSTAFF we do not have households making fixed



2007 eg):


C ¼ α1 Yhde  þ α2 NWh






capital investments, and so the net lending NL





simply by:



of households is given




where α1 and α2 are respectively the propensity to consume from




¼ S :                                                                                                        ð8Þ


disposable income and the propensity to consume from wealth (both assumed constant for the reference scenario) and households' expected disposable income Yhde is given by a simple extrapolation of the trend over the previous period:



The next step in the model is to determine the allocation of net

lending between different assets and liabilities. In the full version of FALSTAFF (Jackson et al., 2014, Jackson et al 2015) we adopt a portfolio allocation function of the form originally proposed by Brainard and Tobin(1968)  andadaptedbyGodley  and Lavoie(2007) tofulfil


0          Yhd


hd    1


this task. For the stationary state version of the model, however, we


1 Y2

Yhde  ¼ Yhd                                                                       



assume simply that households purchase all equities issued by firms






1 @1 þ



hd                   A:                                                                ð5Þ



and absorb the bonds not taken up by banks (and the central bank).




Table 2

Transaction flows matrix for the FALSTAFF stationary state economy.



Households (h)

Firms (f)







Banks (b)








Bank (cb)

Gov (g)

Consumption (C)









Gov spending (G)









Investment (I)









Wages (W)









Profits (P)

+ Pfd + Pbd


+ Pfr


+ Pbr




Depreciation (δ)


+ δ






Taxes (T)









Interest on loans (L)






+ rlL-1





Interest on deposits (D)

+ rdDh


+ rdDf








Interest on bonds (B)

+ rbBh




+ rbBb



+ rbBcb




Change in reserves (R)






+ ΔR



Change in deposits (D)





+ ΔD




Change in bonds (B)







+ ΔB


Change in equities (E)



+ ΔEf


+ ΔEb




Change in loans (L)

+ ΔLh


+ ΔLf

















The change in household deposits is then determined as a residual according to:


where the depreciation, δ, of firms' capital stock K is defined by:


δ ¼ rδ K−1                                                                                                                                                                                                            ð18Þ



x    NLh                     f                                          b                  cb



ΔDh ¼ ma n(        −ΔE  −(ΔB−ΔB  −ΔB



; −Dh








:                       ð9Þ




for some rate of depreciation rδ (assumed constant).

One of the critical decisions that firms must make is how much to in-












So long as NLh −ΔEf −(ΔB −ΔBb −ΔBcb) ≥− D1, households do not need to take out loans. In the case where the supply of equities and the residual supply of bonds exceeds saving, households draw down deposits in order to purchase these assets. Where there are insuf- ficient deposits, ie where NLh −ΔEf −(ΔB −ΔBb −ΔBcb) b − D 1, then households will take out loans ΔLh according to:




vest in each year. We assume here a simple ‘accelerator’ model (Godley and Lavoie, 2007: 227 eg) in which net investment Inet is decided ac- cording to the difference between the actual capital stock at the end of the previous period K-1 and a ‘target’ capital stock Kτ sufficient to meet the expected demand for output, with a fixed capital to output ratio κ. Hence we have:

Inet  ¼ γ(KτK1 )                                                                                           ð19Þ






ΔLh ¼ ΔEf þ  ΔBΔBb ΔBcb



NLh Dh


:                                         ð10Þ




for some ‘accelerator coefficient’ γ, with 0 ≤γ≤ 1, and target capital


Coming next to the firms sector, we assume that this sector supplies











all the goods and services included in the GDP, so that firms' revenues are given by the left hand side of Eq. (1) plus any interest iDf = rDDf received on deposits. From these revenues, firms must pay wages W, distribute dividends P fd, and make interest payments iLf = rLL1 on loans. Wages are calculated according to:



W ¼ wLE;                                                                                                    ð11Þ


where the labour employed LE is given by:




stock Kτ given by:







Kτ ¼ κGDP ;                                                                                                ð20Þ



where GDPe, the expected GDP, is determined (as for disposable in- come) via a simple trend function of the same form as shown in Eq. (5). Gross investment I is then given by:


I ¼ Inet þ δ:                                                                                                    ð21Þ


We assume a funding model for firms in which firms cash flow or retained earnings is equal to the depreciation δ, so that profits, P fd,


LE ¼


η                                                                                                        ð12Þ


distributed as dividends, are equal to profits Pfnet of depreciation.11 In this case, the net lending of firms NLf is given by:


and η is the labour productivity of the economy at time t. Typically, in a capitalist economy, the labour productivity is deemed to grow


NLf  ¼ I







:                                                                                                ð22Þ


over time. If gη is the growth rate in labour productivity, then we can write:


gη t


Net borrowing (negative net lending) of firms is funded by a mixture

of loans ΔLf from banks and equity ΔEf sold to households. The exact split between debt and equity is determined by a desired debt to equity


η ¼ η0 e


;                                                                                                    ð13Þ


ratio ε, such that:



where η0 is the initial labour productivity, and it follows that:







W ¼ η egη t GDP:                                                                                           ð14Þ



We further assume that the wage rate w increases over time at the same rate as labour productivity. In other words, we suppose that workers are paid the marginal product of their labour.10 Wage rates are not suppressed by the power of capital (as might happen for in- stance when unemployment is high); nor do workers exert any upward


Lf  ¼ εEf :                                                                                                        ð23Þ


Assuming that historical debt and equity more or less satisfy this ratio, then firms would be expected to take out net loans ΔLfand issue new equities ΔEfin the same proportions so that:


ΔLf  ¼ εΔE f ;                                                                                                  ð24Þ






from which it is straight forward to show that: 1



pressure on wages (as might happen when unemployment is very low).

In this case it follows that:


w ¼ w0 egη t ;                                                                                                    ð15Þ


ΔLf  ¼

1 þ









and accordingly that wages W are given by:








ΔEf ¼




NLf :                                                                                   ð26Þ


w0 egη t





W ¼ η egη t GDP:                                                                                          ð16Þ



In other words it follows that wages W are a constant proportion w0


of the GDP. Firms' profits Pf(net of depreciation) are then given by:


ð1 þ εÞ


In the event that net investment is negative, ie when firms are in- clined to disinvest in fixed capital, then firms' net lending is positive. We assume first that firms use this cash to pay off loans. In the event that there are no more loans to pay off, firms save excess cash as de- posits with banks.



P f  ¼   1



GDPi þ i  f δ;                                                              ð17Þ


η0                                L                D



10  This assumption is relaxed in the full version of FALSTAFF.


11 It is in principle possible to relax this assumption, but it would immediately lead to positive net investment and accumulation of the capital stock. Since these provide condi- tions for growth in the real economy, they would detract from our desire to eliminate such conditions from the model, in order to test that aspect of the growth imperative that de- rives from interest-bearing money.




The banks sector in FALSTAFF is a simplified accounting sector whose main function is to provide loans ΔLf to (and where necessary to take deposits ΔDf from) firms and to take deposits ΔDh from (and where necessary provide loans ΔLh to) households. In order to meet liquidity needs, commercial banks keep a certain level of reserves R with the cen- tral bank, depending on the level of deposits held on their balance sheet. The additional reserve requirement ΔR in any year is given by:








where the last term is included to offset the purchase of banks bonds by the central banks to meet reserve requirements.

Whereas for firms, capital account positions are determined by the needs of the current account, in the case of banks, we derive the current account balances from the capital account positions, specifically we determine banks retained earnings (undistributed profits) from their fi- nancing needs. Banks income consists in the difference between interest received on loans and government bonds and the interest paid out on







ΔR ¼ ψ  Dh



þ D1


R1                                                                                                                                                ð27Þ


deposits.13 Hence, banks' profits P


are given by:



where ψ is the desired (or required) reserve ratio. Banks ‘pay for’ these reserves by ‘selling’ an equivalent value in government bonds to the central bank, thus depleting their stock of bonds by an amount

ΔBcb equal to ΔR, and increasing the stock of government bonds held by the central bank by the same amount.

To comply with capital adequacy requirements under the long-term targets set out under the Basel III accord, banks are required to hold cap- ital (equity) equivalent to a given proportion of risk-weighted assets. For the purposes of this paper we take the sum of risk-weighted assets to be equal to the sum of loans Lfand Lh to firms and households respec- tively. Banks' capital is defined by the book value of the banks sector eq- uity Eb according to:


Eb ¼ L þ R þ Bb D                                                                                      ð28Þ


where Bbare government bonds held by the banks' sector, D = Df + Dh, and L = Lf + Lh. The long-run Basel III requirement is then met by setting a target capital adequacy ratio φT, such that:




P  ¼ iL f   þ iLh  þ iBb iDh iD f :                                                                          ð34Þ






Banks' saving is equal to the difference between total profits Pband the profits Pbd distributed to households as dividends. Rather than spec- ifying a fixed dividend ratio to determine Pbd and calculating banks' sav- ing Sb from this, we determine instead a desired net lending NLb for banks, according to the financing requirements of banks' capital account and set the saving equal to this. Hence, we have:



NLb ¼ ΔLf þ ΔLh þ ΔBb                        −ΔDh ΔDf  ;                                                  ð35Þ

cap ad



and we can then determine banks' dividends, Pbd, according to:


Pbd  ¼ Pb Sb  ¼ Pb NLb :                                                                               ð36Þ


with NLb given by Eq. (35).






Finally, we describe the government sector accounts. The current ac- count elements14 in the Government's account are relatively simply expressed in terms of the equation:



φT  ¼


L  ¼ 0:08:                                                                                           ð29Þ




¼ S    ¼ TGiB ;                                                                                  ð37Þ




Assuming initial conditions in which this requirement is met, then the capital adequacy ratio is maintained by the banks' sector, provided that:


where taxes, T, are given by:


T ¼ θYh ;                                                                                                        ð38Þ






ΔEb ¼ φT LEb




:                                                                                         ð30Þ



and the interest, iB, paid on government bonds is given by:



In other words, banks' issue new equities (to the households sector)

equivalent to the shortfall between the required capital adequacy pro- portion of loans and the equity value in the previous period.12 It is


iB ¼ i h  þ i b  ¼ rB ( h




B                B                           B−1









þ B1




:                                                                ð39Þ


worth emphasising here that loans and deposits are determined by de- mand (from the household and firms sectors), reserves are determined by the reserve requirement and equities are determined by the capital adequacy requirement. The final discretionary element on the banks' balance sheet is government bonds, which we assume that banks will

hold in preference to reserves where they can – ie once the reserve

requirement is met – because they bring income from interest. The tar- get value of banks' bonds BbT can be determined from Eq. (28) as:


BbT  ¼ DRL þ Eb :                                                                                      ð31Þ


Note that no interest is included for government bonds owned by

the central bank, as profits from the central bank are assumed to be returned directly to the government. The capital aspect of the govern- ment account is simply a matter of establishing the level of government debt, through the change in the stock of outstanding government bonds, B, according to:


ΔB ¼ −NLg :                                                                                                 ð40Þ


When the government runs a fiscal deficit, the net lending, NLg, is negative leading to an increase in the stock of outstanding bonds. In



Or equivalently, using the reserve requirement to determine R and the capital adequacy ratio to determine Eb, we can write:


the event that government runs a fiscal surplus, NL

stock of outstanding bonds declines.


is positive and the


BbT  ¼ Dð1−ψÞ−Lð1−φÞ:                                                                            ð32Þ


Again assuming initial conditions meet this requirement, then banks target for holding government bonds is met, provided that:


A key feature of stock-flow consistent models is that they explicitly

satisfy a key condition that prevails in the macroeconomy, namely that sum of net lending across all sectors is equal to zero. In other words:


NLh þ NLf  þ NLb þ NLg ¼ 0:                                                                           ð41Þ






ΔBb ¼ BbT Bb



þ ΔBcb ;                                                                             ð33Þ



13 We omit here for simplicity interest paid on reserves. In the event that this was includ- ed in the model, it would simply represent a transfer from the central bank (essentially from government) to banks. We note here also that the banks sector does not pay wages


12    We assume in this version of FALSTAFF that households purchase all equities issued by

the banks sector and that the market value of equities so issued is determined by the book value of equity.


in FALSTAFF. These are deemed to be paid via the firms sector as are public sector wages.

14   In keeping with National Account conventions, the current and capital elements of the government sector are not shown in separate accounts in Table 2.




Or in other words, using Eqs. (7), (8), (22), (35) and (37) above, we should expect that:


Yhd CInet þ Pb Pbd þ TGi h i ¼ 0:                                                   ð42Þ


illustrate this stationary state solution with specific numerical values, check its evolution over time, and explore what happens when the sys- tem is pushed away from equilibrium.


B              B

4. Numerical Simulation


Noting that Y hd + T = Yh and using Eq. (2), it follows that:


W þ P fd þ ih i h  þ Pb i ¼ C þ G þ Inet :                                                   ð43Þ

D              L                               B


Since P fd = P fand noting that Pb can be expanded (Eq. (34)) as a sum of interest receipts (and payments), we can show that Eq. (43) can be rewritten as:


W þ P f  þ i f i ¼ C þ G þ Inet                                                                                                                                       ð44Þ



We select first a range of numerical values to initialise the variables in FALSTAFF as detailed in Appendix 1. Drawing from empirical data in Canada and the UK,15 we select values that could reasonably be taken to describe an advanced western economy. The initial GDP of $2 trillion is broken down between consumption (60% of GDP), government ex- penditure (20%) and gross investment (20%). We assume an initial cap- ital stock value of $6 trillion suggesting a capital-to-output ratio of 3. For

the economy not to be growing in real terms, this means that the depre-


L              D

ciation rate is approximately 7%, so that gross investment just covers the


or equivalently that:


W þ P f  þ i f  þ δ ¼ C þ G þ I                                                                         ð45Þ


which is precisely (see Eq. (1)) where we started from. The net lending condition is therefore a useful consistency check for the validity of the model as a whole and will be one of the aspects tested across different scenarios in the numerical simulations.

Having established the accounting identities and behavioural rela- tionships of the FALSTAFF model, we next need to determine some ini- tial values consistent with stationary (or quasi-stationary) solution. For the purposes of this exercise, this means that there should be no long-

term drivers of growth in the ‘real economy’. So, for instance, we

would expect no net accumulation of the productive capital stock K. Specifically this means setting the initial gross investment, I0, in produc- tive capital equal to the initial depreciation δ0:

I0  ¼ δ0  ¼ rδK0 ;                                                                                              ð46Þ


where rδis the depreciation rate and K0 denotes the value of the cap- ital stock at time t = 0. In addition, government spending is assumed not to grow over time and government debt does not accumulate over time. This means setting initial government expenditure G0 and the ini- tial household income tax rate T0 so that government achieves a fiscal balance:


G0 þ rBB0 ¼ T0 ;                                                                                             ð47Þ


where rB is the rate of interest on government bonds (assumed con- stant) and B0 is the stock of outstanding bonds at time t = 0. From Eqs. (46) and (47) it follows that:


NLf  ¼ NLg  ¼ 0;                                                                                             ð48Þ


depreciation of capital. The national income (GDP minus depreciation) is assumed to be split initially between wages (returns to labour) and profits (return to capital) in the ratio 60:40.

Firms' productive capital stock is assumed to be capitalised equally between debt ($3 trillion in loans from banks) and equity ($3 trillion in shares held by households). The accelerator constant γ in the invest- ment function is taken initially as 0.1.16 A smaller amount of equity ($887 billion) is invested in banks, sufficient to provide an initial rate of return on equity (banks dividends divided by the equity) equal to the rate of return on firms equity. In addition to equity holdings, house- holds are also deemed initially to hold $1 trillion in deposits and an equal amount in government bonds. Interest rates of 1% (on deposits), 2% (on bonds) and 5% (on loans) are set exogenously.17

A capital adequacy ratio for banks is set at 8% and the desired reserve ratio for banks holdings of central banks reserves is set at 5%. These pa- rameters in their turn determine the level of bond holdings by the banks, reserve holdings by banks and bond holdings by the central bank (equal to the reserve holdings of banks). The sum of bond holdings by households, banks and the central bank is taken as the initial stock of government debt. Using the exogenous bond interest rate, it is then pos- sible to calculate the initial interest burden on government which, to- gether with the exogenous initial government expenditure, must be met by taxation. Using households' total income, this enables us to cal- culate (see Eq. (50) above) a tax rate on households sufficient to ensure a balanced fiscal budget equal to the initial target government spending plus the interest rate on bonds held by households and by banks. For the parameters given above this turns out to be approximately 26%.

Finally, we assume a level of the workforce required to produce the output in the FALSTAFF economy with an initial unemployment rate of 7%, typical of advanced economies. From these initial values, we con- struct eight separate scenarios to test the hypothesis that positive inter- est rates lead to a growth imperative. The first six of these scenarios are

initialised using parameters consistent with a stationary state and are


0                     0

defined as follows:


and hence that:


NLh þ NLb ¼ 0;                                                                                              ð49Þ














0                                                                                                                                                                          0




For stationary state solution, as Godley and Lavoie (2007: 73) point out, the net lending NLh of the household sector must also be equal to zero. Otherwise, it is clear to that NW h would either rise or fall, leading to rising or falling consumption. This means that the initial value C0 of household consumption must be equal to the initial disposable income  Yhd. This can be satisfied by choosing a tax rate θ at which Eq. (47) is satisfied. Since T0 = θ0Yh, we can use Eq. (2) to deduce that:


G0 þ rBB0



    Scenario 1: the model is run using the values established in Appendix 1 with no adjustments;

    Scenario 2: the model is run with a small (max ± 2.5%) random vari-

ation to consumer demand in each year;

    Scenario 3: the model is run using a small (5%) one-off shock (reduc- tion) in consumer demand in year 20;

    Scenario 4: government responds to Scenario 3 with a ‘strict’ austerity

policy in which the initial fiscal balance is maintained, no matter what;

    Scenario 5: firms respond to Scenario 3, with a version of Keynes'


15  Data for the Canadian economy may be found in the Cansim online database: http://


θ0  ¼ W


P fd


bd            Bh


Dh          Lh :                                                      ð50Þ; and for the UK economy on the Of-


0 þ  0  þ P0   þ i0  þ i0  i0


In short, conditions (46) to (50) define an initial state consistent with a stationary solution to the model. In the following section, we



ce for National Statistics online database: html?nscl=Economy#tab-data-tables.

16  See for example Tutulmaz and Victor, 2013.

17   As with most of the variables in the model, these values can be selected by the user.




Fig. 2. GDP on an expenditure basis (Scenario 1).



‘animal spirits’, in which more is invested when things are going well (ie when expected output rises) and less when they are going worse (ie  when  expected  output  falls);

    Scenario 6: governments respond to the conditions in Scenario 5, by

engaging in counter-cyclical spending.



Finally, we explore a scenario in which the economy is initially growing and then moves towards a stationary state.


    Scenario 7: government expenditure is assumed to grow at 2% per annum for the first three periods of the run; this growth rate the de- clines to zero over the subsequent decade and remains at zero for the rest of the run.



The results of Scenario 1 are illustrated in Figs. 2 and 3. Fig. 2 shows the GDP on an expenditure basis. The graph itself is not particularly in- teresting other than that it confirms, as expected, that with a suitable choice of initial values, a stationary state economy is possible. More in- teresting for our purposes in this paper is that this result is obtained from an economic model with interest-bearing debt, and in spite of the fact that banks are subject to both a capital adequacy requirement and a reserve ratio requirement.

Since net lending in the stationary state is equal to zero for all sec- tors, it is to be expected, and Fig. 3 confirms, that the net financial worth of each of the FALSTAFF sectors remains unchanged over the pe- riod of the run. Fig. 3 also illustrates one of the fundamental accounting identities of the stock-flow consistent model, namely that the sum of all financial assets and liabilities across all sectors, ie the net financial worth of the economy as a whole, is zero.

It is not possible in the space of this paper to illustrate, although the reader can verify for themselves in our online model, that the results in Figs. 2 and 3 do not depend on specific values chosen for the interest rates on deposits, loans and bonds;18 nor do they depend on the specific values chosen for capital adequacy or reserve ratio; although, not sur- prisingly, the steady state tax rate (Eq. (50)) changes when these pa- rameters are altered. In short, the results of Scenario 1 appear to

indicate that there is no categorical ‘growth imperative’ embedded in


18 Explicitly, these results were tested for deposit rates between 0 and 10% and for loan rates between 0 and 15% (with an interest rate spread between 0% and 10%). The interest- ed reader may check for themselves using our online model at: FALSTAFF_steadystate.


the structure of a credit-based money system with interest-bearing debt in the capitalist economy.

Our next aim is to test the robustness of this finding, once values de- part from the equilibrium values defined at t = 0. Scenario 2 subjects consumer demand to a small random variation within a range of

± 2.5% of the initial value, C0, of consumer demand. In other words, within each period consumer spending is assigned a random value in the range [0.975C0,1.025C0]. All other initial values for both stocks and flows are the same as in Scenario 1. The impact on the growth rate from this variation is shown in Figs. 4 and 5.

Although Fig. 4 shows considerable variation in the short term growth rate (within a range of less than ±1%) it is clear that the long-run growth rate is still around zero. Certainly there is no obvious systematic expan- sion of the economy, even though the net lending positions of the differ- ent sectors (Fig. 5) vary considerably over the run. Again, variations in deposit, loan, and bond rates and in the capital adequacy requirement and the reserve ratio make no appreciable difference to this long-term trend, or indeed to the amplitude of the variations around it. We could de- scribe the economy illustrated in Figs. 4 and 5 as a quasi-stationary-state economy with a long-run average growth rate of zero. Notice that the sum of net lending remains zero across the run, in spite of the variation in net lending in individual sectors. This is an indication that the model is working consistently, and reflecting correctly the accounting identities that must hold in any real economy. Though the pattern looks rather dra- matic, notice that the amplitude of the variations in net lending is not high

— less than 0.5% of the GDP in most cases.

Scenario 3 tests the resilience of the stationary state solution under a single consumption shock. Consumer demand is depressed by 5% in pe- riods 20 and 21 of the scenario, and thereafter returns to the initial value. All other values are unchanged. The results of this scenario are il- lustrated in Figs. 6 and 7. As might be expected, Fig. 6 shows a sharp downward spike in the growth rate, followed by a sharp upward spike

(above the long-run zero growth rate) as ‘normal’ consumption behav-

iour resumes in period 22. Thereafter, the growth rate rather quickly returns to something close to zero, but tends to oscillate around zero for some time, approaching zero asymptotically as the economy ‘settles

down’ again.

The net lending behaviours of different sectors (Fig. 7) show a simi- lar pattern, with rather high initial movements away from the equilibri- um position, which tend to attenuate over time as the growth rate flattens towards zero. Fig. 7 reveals that some individual sectors switch from being net lenders to net borrowers and back again several times during this process of readjustment. As in Fig. 5, only the banking sector maintains a net lending position very close to zero. In spite of having the




Fig. 3. Financial net worth of FALSTAFF sectors (Scenario 1).




flexibility to retain some proportion of profits in order to meet financing needs (Eq. (32)), this turns out not to be necessary most of the time, with the outlay on new loans, bonds and reserve requirements more or less matching the inflow of new deposits. The sector most negatively affected in the early years following the shock is the government sector which experiences a dramatic increase in the deficit.

At this point, the government is faced with some critical choices about how to respond. Instinctively, of course it may want to respond to the increased deficit either by increasing taxation or by reducing

spending. In Scenario 4, we test the outcome of strict ‘austerity’ policy

on the shock introduced in Scenario 3. Fig. 8 provides a graphic illustra- tion of how things can go wrong if governments cut back spending too fast in order to reduce a fiscal deficit. In this (admittedly extreme) case, the government insists on trying to return the fiscal deficit to zero, resulting in a spectacular collapse of the FALSTAFF economy.

It is also useful to think a little about the potential responses of firms to the sudden change in circumstances represented by the one-off con- sumption shock established in Scenario 3, in particular in relation to their investment behaviour. The investment function introduced in


Eq. (19) sets out a behavioural response by firms to changes in expected demand, depending on two factors:

Inet  ¼ γ(KτK1 ):                                                                                          ð51Þ


The first factor (represented by the expression in brackets in Eq. (51)), is the perceived shortfall or surplus in capital stock, deter- mined on the basis of a target capital stock required to meet the expect- ed demand. If expected demand rises, the target capital will be higher than the capital in the previous year, and so the expression in brackets will be positive and firms will seek to undertake net investment. In this case, gross investment is greater than the depreciation of the capital stock. If expected demand falls, the expression in brackets will be nega- tive and firms will seek to disinvest. In this case the gross investment is less than the depreciation of the capital stock.

The second key element in Eq. (51) is the ‘accelerator coefficient’, γ,

which is a measure of the desired ‘speed of adjustment’ undertaken by

firms in response to changes in demand. Higher values of γ will increase the responsiveness of firms to a change in demand, lower values of γ





Fig. 4. Growth rate under random uctuations in consumer demand (Scenario 2).




Fig. 5. Net lending under random uctuations in consumer demand (Scenario 2).



Fig. 6. Growth rate after a one-off negative consumption shock (Scenario 3).




will decrease the responsiveness. A higher value for γ can be thought of as capturing a high degree of what Keynes (1936) called ‘animal spirits’; that is: a greater willingness amongst entrepreneurs to invest when times are good, and a lower willingness to invest when things are not

going so well. To test the impact of animal spirits on the FALSTAFF econ- omy, in the wake of a consumption shock, we looked at the impact of in- creasing the γ coefficient (from 0.1 to 0.15) throughout Scenario 5. The result is illustrated in Figs. 9 and 10.

We assume in this exercise that animal spirits are a long-term feature of the economy and do not change over time. So the new value of γ is ap- plied from the beginning. Interestingly, this has no impact while the econ- omy is in a stationary state. This is because the capital shortfall (the expression in brackets in Eq. (51)) is zero during this time. Consequently the value of the accelerator coefficient is irrelevant. Once the economy is shocked out of its stationary state however, things are different: the higher coefficient immediately sets in motion a cyclical pattern of increas- ing amplitude, with every sign of becoming unstable.19 In the real world such a dynamic would lead to numerous uncomfortable consequences,


19   In fact, running the model to 200 periods reveals a collapse in stability.


including high unemployment, price instability, and widely fluctuating net lending positions (Fig. 10).

A core concept in Keynesian and post-Keynesian economics is the idea of countercyclical spending; that is: the idea that governments can play a useful stabilising role in an unstable economy by increasing spending when output is falling and reducing spending when output is rising. In Scenario 6, we explore the impact of countercyclical spending as a possi- ble policy response to the situation in Scenario 5. Following the consump- tion shock (as in Scenario 3) in an economy with high animal spirits (as in Scenario 5), the government in the FALSTAFF economy responds by in- creasing spending at the same rate as the expected aggregate demand is falling when the economy is in recession and reducing spending at the same rate as expected aggregate demand is rising when the economy is growing. The consequences on the growth rate are illustrated in Fig. 11, where we also show for comparison the growth rates for scenarios 3 and 5. Remarkably, a countercyclical spending response more than com- pensates for the destabilising influence of animal spirits following the de- mand shock. The FALSTAFF economy is returned more quickly to a quasi- stationary state than in scenario 3, with only slight long-run deviations from zero growth and no net accumulation.




Fig. 7. Net lending after a one-off negative consumption shock (Scenario 3).




Fig. 8. Economic collapse from strict austerity after a negative shock (Scenario 4).





Finally, we explore a scenario in which the economy is initially growing, in other words where the economy starts away from the sta- tionary equilibrium. We are interested to find out if the ability to achieve a stationary state depends on a particular starting position, in which the sectors are all in balance, with no net lending and zero growth. What would happen if the economy was already growing, and accumulating debts or assets in different sectors? Is it still possible to move towards a stationary or quasi-stationary state from these con- ditions with positive interest rates? Or is such an economy destined to either grow for ever or become unstable?

In Scenario 7 (Figs. 12 and 13), we suppose that the initial growth rate in government spending is 2% per annum, and that the initial ex- pected growth in output, disposable income and household wealth is also 2% per annum. We assume that these conditions pertain for the first three periods of the scenario, but that after this point, government begins slowly to reduce the growth rate in spending until by period 13 of the run, it has declined to zero. Fig. 12 illustrates this transition in terms of the GDP for the FALSTAFF economy. It appears that the transi- tion to a (quasi-) stationary state is indeed possible; but it takes some


time before the perturbations induced by ‘animal spirit’ responses die down. These oscillations are also visible in the net lending positions (Fig. 13). Again it can be shown, that countercyclical spending by gov- ernment  dampens  the  oscillations  associated  with  this  transition.20

Fig. 12 also shows that the pattern of transition in the GDP is echoed in the money supply. It is interesting to note, however, that the oscilla- tions in the money supply lag those in the GDP, suggesting that in the FALSTAFF economy at least, changes in the money supply are driven by what is happening in the real economy, rather than the other way around. Increased output demands increased loans from firms creating a higher level of deposits from households. Fig. 13 also shows the veloc- ity  of  circulation  of  money  which  is  calculated  endogenously  in




20 If growth in the economy is declining faster than the desired growth rate, government spending is increased above the target rate. If it is declining slower than the desired rate, spending growth is reduced faster than the target rate. See Scenario 8 in the online version of the model at:




Fig. 9. The growth rate after a demand shock with animal spirits (Scenario 5).



Fig. 10. Net lending after a demand shock with animal spirits (Scenario 5).





FALSTAFF through the ratio of GDP to the money supply.21 Because money supply lags demand, the velocity of money increases initially in  order  to  maintain  aggregate  demand.


5. Discussion


The aim of this paper was to explore the potential for a stationary (non-growing) economy in the presence of credit creation and interest-bearing debt. To this end, we presented a stock-flow consistent

(SFC) system dynamics model (FALSTAFF) of a hypothetical closed



requirements on banks to maintain a minimum positive capital adequa- cy ratio and sufficient central bank reserves. Contrary to claims in the lit- erature, we found no evidence of a growth imperative arising from the existence of a debt-based money system per se.

In fact, we presented a variety of scenarios which exemplified quasi- stationary states of various kinds, and which offered resilience from in- stability in the face of random fluctuations, demand shocks, and exag-

gerated ‘animal spirits’. We also simulated a transition from a growth-

based economy towards such a state. None of the scenarios were sensi- tive to modest changes in the values for interest rates on deposits, loans



economy with private ownership and credit-based money. Behavioural


and government bonds.


Perhaps most significantly from our point of


aspects of the model include the propensity to consume out of both in- come and wealth, a simple accelerator model of firms' investment, and


view, these conclusions are not changed by imposing demands on

banks to maintain a given capital adequacy ratio or to hold a given






21 Since prices are not included in the model, conventional formula Mv= pT, where M is the money supply, v the velocity of money, p the price level and T the volume of transac- tions, reduces to MV=GDP. GDP is given by the model; M is taken as the sum of deposits and reserves and V can then be calculated as V =GDP/M.


22 A sensitivity analysis was conducted in FALSTAFF for values of the interest rate on loans between 0 and 15%, and on bonds and deposits between 0 and 10%. Slight increases in the amplitude of oscillations was observed at higher interest rates, under conditions of shock. But the conclusions observed in this paper still held.




Fig. 11. Stabilising influence of countercyclical spending after a demand shock with animal spirits (Scenario 6).





ratio of central bank reserves to bank deposits. The only scenario in which instability led to economic collapse was the one in which we im- posed a ‘strict’ austerity policy in response to a negative shock to con- sumer demand. In this case, it was the austerity policy, rather than the existence of debt, that crashed the model.

The fact that the charging of interest on its own does not lead to a growth imperative could perhaps have been inferred from the realisa- tion that the only interest payments which contribute directly to the GDP are the net interest payments of firms. All other interest payments turn out to be transfers between sectors and neither restrict nor en- hance aggregate demand in themselves. Clearly net interest payments of firms will increase if firms' loan requirements expand; and this will happen if, for instance, firms decide to expand investment. But in this case, growth is driven directly by expansion in aggregate demand, not by the charging of interest in itself.


Slightly more surprising perhaps is that neither capital adequacy nor reserve ratio requirements change this conclusion. At the heart of the growth imperative hypothesis lies the claim that banks' cap-

ital is somehow money that is ‘withheld’ from the economy. Admati

and Hellwig (2013:6) claim that this view arises from a misunder- standing of banks' capital as “cash that sits idly in the bank's tills without being put to work in the economy”. In their view, this is a deliberate misrepresentation propagated by the banking lobby to “confuse regulatory debate” (Ibid). Irrespective of this point, our analysis confirms that these regulatory initiatives act neither to

reduce the potential for debts to be serviced nor to expand aggre- gate demand.

The exercise in this paper is subject to a number of caveats and lim- itations. In the first place, we assumed a ‘closed’ economy, in which net trade was zero throughout. In addition, prices were excluded from the






Fig. 12. GDP and the money supply during transition to a stationary state (Scenario 7).




Fig. 13. Net lending positions during transition to stationary state (Scenario 7).





model, meaning that inflationary or destabilising price effects could not be explored. In Scenarios 1 to 6, we deliberately chose values for key variables such that real economy aggregates were not introducing expansionary effects. For instance, the model assumes no demographic changes which might require a rise in government expenditure even for a non-expanding population. Taxation is initially set so that government debt does not accumu- late. Firms financing behaviour is determined in such a way as not to accumulate capital assets beyond those deemed necessary to satisfy expected demand. There is no attempt to model housing investment and house price inflation, both of which may well in- troduce expansionary dynamics into the economy. Some of these assumptions can be relaxed by the user in the online version of the model. Others are the subject of ongoing exploration (Jackson et al 2015).

It should be noted, in particular, that we have not included certain microeconomic behaviours which might be expected to lead to specifically both to a heightened monetary expansion and also to aggregate demand growth or perhaps instability. For instance, it is clear that competitive (positional) behaviour by firms through profit maximisation could expand investment (particularly when finance is cheap) in order to stimulate de- mand (Gordon and Rosenthal, 2003). Neither do we attempt here to model Minsky-like behaviour in which progressive over-confidence amongst lenders leads to an expansion of credit, over-leveraging and eventual financial instability (Minsky, 1994, Keen, 2011).

It is also worth pointing out that, in spite of the findings in this paper, there area number ofgood arguments against private interest-bearing debt as the main means of creation (and destruc- tion) of the money supply. As a wide variety of authors have pointed out,23 this form of money can lead to unsustainable levels of public and private debt, increased price and fiscal instability, speculative behaviour in relation to environmental resources, greater inequality




23 Useful critiques of debt-based money can be found in Sigurjónsson, 2015, Daly, 2014, Wolf, 2014, Farley et al., 2013, Jackson and Dyson, 2012, Huber and Robertson, 2000, as well as the ground-breaking, early work from Douthwaite (1990). The idea of eliminating banks' ability to create money can be traced to Frederick Soddy (1931); for a useful histor- ical overview see Dittmer, 2015.


in incomes and in wealth, and a loss of sovereign control of the money system. We are therefore firmly of the opinion that monetary reform is an essential component of a sustainable economy. We re- gard the current study as an important way of distinguishing where effort should be placed in transforming this system. Specifi- cally, the results in this paper suggest that it is not necessary to elim- inate interest-bearing debt per se, if the goal is to achieve a resilient, stationary or quasi-stationary state of the economy.

It is also worth reiterating that, aside from the question of interest-bearing money, there exist several other incentives to- wards growth within the architecture of the capitalist economy. We have elucidated some of these incentives elsewhere (Jackson, 2009, Victor, 2008, Jackson and Victor, 2011). They must be taken to include, for instance: profit maximisation (and in particular the pursuit of labour productivity growth) by firms, asset price specula- tion and consumer aspirations for increased income and wealth. Some of these mechanisms also lead to potential instabilities in the capitalist economy. Many of them are reliant on the existence of credit-based money systems. Minsky (1994), perhaps most famously, has shown how cycles of investment and speculation, built around debt-based money, can lead to endemic instability. But this logic does not entail that interest-bearing money, in and of itself, creates a growth imperative.

Interestingly, the exercise in this paper has shown that, in spite of these incentives, a transition to a stationary economy from a growth- based economy is theoretically possible. We have illustrated in particu- lar the role of countercyclical spending by government in smoothing that transition. Encouragingly, we have shown that it is possible to get from a growth-based economy to a quasi-stationary state without ei- ther destabilising the economy or dismantling the concept of interest- bearing debt.




The authors gratefully acknowledge support from the Economic and Social Research Council (ESRC grant no: ES/J023329/1) for Prof Jackson's fellowship on prosperity and sustainability in the green econ- omy ( which has made this work possible. The present paper has also benefitted from a number of constructive com- ments (including some detailed discussions on the behaviour of banks) from Herman Daly, Ben Dyson, Graham Hodgson, Andrew Jack- son, Bert de Vries, and three anonymous referees.



Appendix 1

Initial values for FALSTAFF scenarios.

Sources for reference values: see note 16.


Variable                                                    Values        Units                Remarks


Initial GDP                                                 2000           $billion             UK GDP is currently around £1.6 trillion; Canada GDP is around CAN$1.9 trillion.

Initial consumer spending C                           1200           $billion             Assumes consumer spending is approximately 60% of GDP, typical for advanced western economies Propensity to consume from wealth (α2)                                 0.034                           We assume a small propensity to consume from wealth equivalent to $200 billion, consistent with

empirical data.

Propensity to consume from income (α1)            0.83                                Calculated as the ratio of non-wealth consumption ($1 trillion) to initial disposable income Initial government spending G                                                   400          $billion             Assumes government spending of 20% of GDP

Initial gross investment I                                400          $billion             Assumes investment of 20% of GDP

Initial depreciation                                        400          $billion             Assumes that gross investment equals depreciation.

Initial depreciation rate                                      6.67% %                     Chosen so that depreciation is equal to gross investment. Typical rates in advanced economies are around 68% Initial National Income                                          1600           $billion             Calculated by subtracting depreciation from GDP.

Initial wages (W)                                           960          $billion             Assumes labour's share of income is around 60% of the national income, typical in both Canada and the UK Initial profits (P)                                                                 640          $billion             Calculated by subtracting labour's share of income from the National income

Initial capital stock (K)                                 6000           $billion             Based on the chosen estimate of capital to income ratio Initial capital to income ratio                                                3                                Ratio in Canada is a little under 3; in UK around 5.

Initial investment accelerator (γ)                        0.1                              Typical range for advanced economies: 0.080.15

Initial firms debt Df                                                                         3000           $billion             Capitalisation split equally between debt and equity Initial firms' loans Lf                                                                                                          1000           $billion             Included  for completeness

Initial firms equity Ef                                                                      3000           $billion             Capitalisation split equally between debt and equity

Initial banks equity Eb                                                                        320          $billion             Calculated as the difference between banks' assets and liabilities other than equities Initial household deposits Dh                                                                                                  3000           $billion             Consistent with the assumption that (broadly speaking) loans are equal to deposits Initial household loans Lh                                                                                                         1000           $billion             Included for completeness

Initial household bond holdings Bh                                      1000           $billion             Leads to a debt-to-GDP ratio close to current levels Interest rate on deposits                                                    1%          %                     Typical of current values

Interest rate on government bonds                   2%          %                     Typical of current values Interest rate on loans                                                 5%          %                     Typical of current values

Initial reserve ratio                                        5%           %                     High by pre-crisis standards; low by post-crisis standards. Initial banks reserves R                                                    200          $billion             Chosen for consistency with reserve ratio

Initial central bank bonds Bcb                                                  200          $billion             Chosen for consistency with capital adequacy ratio Banks capital adequacy ratio                                    8%           %                     Consistent with Basel III banking regulations

Initial banks bonds Bb                                                                       120          %                     Consistent with chosen capital adequacy ratio, taking into account banks' reserve holdings. Initial government debt B                                      1320           $billion             Equal to the total of household, bank and central bank bond holdings

Initial household tax rate                               26%          %                     Calculated from initial household income at a level that will lead to a zero fiscal balance for government Initial unemployment rate                                        7%           %                     Typical of both Canada and the UK over the last few years.

Initial workforce                                             21.5        Million             Workforce is typically 45%55% of population.

Initial labour productivity                                   1          $m GDP/emp Consistent with initial GDP delivered by the initial workforce at the given unemployment rate.




Appendix 2

Initial balance sheet for FALSTAFF scenarios.







Gov                                  Totals

Net Financial Worth









–                                     12,840




–                                     4000



–                                     4000



–                                     3320





–                                     1320



–                                     200






1320                                 12,840



–                                     4000




–                                     4000




–                                     3320


1320                                 1320



–                                     200





Admati, A., Hellwig, M., 2013. The Bankers' New Clothes: What's Wrong With Banking  and What to Do About it. Princeton University Press, Princeton, NJ.

Binswanger, M., 2009. Is there a growth imperative in capitalist economies? A circular

flow perspective. J. Post Keynesian Econ. 31 (2009), 707727.

Binswanger, M., 2015. The gGrowth iImperative revisited. A rejoinder to Gilanyi and John-  son. J. Post Keynesian Econ. 37 (4), 648660.

BIS, 2011. Basel III: A Global Regulatory Framework for More Resilient Banks and Banking Systems. Basel Committee on Banking Supervision. Bank for International Settle-  ments, Basel.

Brainard, W., Tobin, J., 1968. Pitfalls in financial model building. Am. Econ. Rev. 58 (2),  99122.

Caverzasi, E., Godin, A., 2015. Post-Keynesian stock-flow-consistent modelling: a survey.

Camb. J. Econ. 39 (1), 157187.

Copeland, M.A., 1949. Social accounting for money flows. Account. Rev. 24 (3), 254264.  Daly, H., 2014. From Uneconomic Growth to a Steady-State Economy. Edward Elgar,



Dittmer, K., 2015. 100 per cent reserve banking: a critical review of green perspectives.

Ecol. Econ. 109, 916.

Douthwaite, R., 1990. How Economic Growth Enriched the Few, Impoverished the Many and Endangered the Planet. Green Books, Cambridge.

Douthwaite, R., 2006. The Ecology of Money. Green Books, Cambridge (Online at: http://

Eisenstein, C., 2012. We can't grow ourselves out of debt, no matter what the Federal Re- serve does Guardian, 13th Sept: sep/03/debt-federal-reserve-fixation-on-growth.

Farley, J., Burke, M., Flomenhoft, G., Kelly, B., Forrest Murray, D., Posner, S., Putnam, M., Scanlan, A., Witham, A., 2013. Monetary and fiscal policies for a finite planet. Sustain- ability 5, 28022826.

Godley, W., 1999. Seven unsustainable processes: medium term prospects for the US and for the world. Levy Economics Institute, NY (Online at: pubs/sevenproc.pdf).

Godley, W., Lavoie, M., 2007. Monetary Economics An Integrated Approach to Credit,

Money, Income, Production and Wealth. Palgrave Macmillan, London.

Gordon, M., Rosenthal, J., 2003. Capitalism's growth imperative. Camb. J. Econ. 27, 2548.




Hahn, Matthews, 1964. The theory of economic growth: a survey. Econ. J. 74 (296), 779902.

Huber, J., Robertson, J., 2000. Future Money. New Economics Foundation, London.

Jackson, A., Dyson, B., 2012. Modernising Money: Why Our Monetary System is Broken and How it Can be Fixed. Positive Money, London.

Jackson, T., 2009. Prosperity Without Growth Economics for a Finite Planet. Routledge,


Jackson, T., Victor, P., 2011. Productivity and work in the new economy: some theoretical reflections and empirical tests. Environ. Innov. Soc. Trans. 1 (1), 101108.

Jackson, T., Victor, P., Naqvi, A., 2015. Towards a stock-flow consistent ecological macro- economics. PASSAGE Working Paper 15/02. University of Surrey, Guildford.

Jackson, T., Victor, P., 2015. Does low growth increase inequality? Some theoretical reflec- tions and numerical simulations. Ecol. Econ. 2015.03.019.

Jackson, T., Drake, B., Victor, P., Kratena, K., Sommer, M., 2014. Literature Review and Model Development. Workpackage 205, Milestone 28, Wealth, Welfare and Work for Europe. WIFO, Vienna.

Jorgenson, D.W., 1963. Capital theory and investment behavior". Am. Econ. Rev. 53 (2), 247259.

Keen,  S.,  2011.  DebunkingEconomics  Revised  and  Expanded  Edition.  Zed  Books,

London and New York.

Keynes, J., 1936. The General Theory of Employment, Interest and Money. Palgrave Macmillan, London.

Lavoie, M., Godley, W., 2001. Kaleckian models of growth in a coherent stock-flow mon- etary framework: a Kaldorian view. J. Post Keynesian Econ. 24 (2), 277311.


Luxemburg, R., 1913. The Accumulation of Capital. 1951 edition by Dr. W. Stark.

Routledge and Kegan Paul, London.

Marx, K., 1867. Capital Volume 1. Trans. Ben Fowkes (1990). Penguin Books, London.

Mill, J.S., 1848. Of the stationary state. Principles of Political Economy (Online at: http://

Minsky, H., 1994. Financial Instability and the decline (?) of banking: public policy impli- cations. Hyman P. Minsky Archive (Paper 88. archive/88).

Piketty, T., 2014. Capital in the 21st century. Harvard University Press, Harvard.

Rosenbaum, E., 2015. Zero growth and structural change in a post-Keynesian growth model. J. Post Keynesian Econ. 37 (4), 623647.

Sigurjónsson, F., 2015. Monetary reform: a better monetary system for Iceland. A Report Commissioned by the Prime Minister of Iceland (Online at: http://www.

Soddy, F., 1931. Money Versus Man. Elkin Mathews & Marrot, London. Solow, R., 1970. Growth Theory: an exposition. Clarendon, Oxford.

Tutulmaz, O., Victor, P., 2013. Labor oriented stock adjustment model estimations of total investment for Canadian industries. Int. Proc. Econ. Dev. Res. 69, 1824.

Victor, P., 2008. Managing Without Growth Slower by Design, not by Disaster. Edward

Elgar, Cheltenham.

Wolf, M., 2014. Strip private banks of their power to create money. Financ. Times (April 25th 2014).