Tag Archives: Keynes

On the Determinants of Investment

It is well known that an economy’s output levels and employment levels are determined by the level of investment. The popular story presented in mainstream textbooks and taught in conventional courses is that of planned saving adapting to planned investment, with the rate of interest as the equilibrating factor. This is the supply-side vision of the economy wherein demand can never be a constraint except temporarily due to frictions or imperfections. Additionally, this view reaches the conclusion that that there is a tendency to full-employment in capitalist economies. This blog post revisits the saving-investment relationship, the investment function and the link between the rate of interest and investment. Given the crucial role investment plays in an economy, it is important that we critically appraise its determinants.

By investment, economists mean the purchase of capital goods and not financial assets. Saving refers to the income that is not consumed. Saving is a leakage from the economy while investment is an injection. Marginalist (neoclassical) economics maintains that planned saving and planned investment are equilibrated through variations in the rate of interest which is assumed to be sufficiently sensitive to any saving-investment disequilibrium. Planned saving is a positive function of the rate of interest while planned investment is a negative function of the rate of interest. When planned saving is in excess of planned investment, there is excess savings which puts a downward pressure on the rate of interest and vice versa. However, is such an a priori functional link between the rate of interest and the rate of accumulation a correct one? The 1960s capital theory debate demonstrates the implausibility of an interest-elastic investment function on logical grounds. Also, in a world where the rate of interest is set by monetary policy (and therefore exogenous to the saving-investment process) it is unclear how it can play the role of an equilibrating force as suggested by marginalist economics.

The non-orthodox approach to activity levels and growth draws inspiration from the principle of effective demand of Kalecki and Keynes. The investment function is not interest-elastic in this theoretical approach, also called the demand-led approach. Here, investment depends on ‘the future expected level of effective demand (D+1), which tells us how much capacity firms will need, and on the current technical conditions of production (represented in this simple model by the normal capital-output ratio)…’ (Serrano 1995: 78; available freely here). In this simple model, note that production is assumed to be carried out with circulating capital only. So, I = aD+1 where a is the capital-output ratio. A change in technology will affect the capital-output ratio, which indicates how much of capital is required to produce one unit of output. Further, we make the realistic assumption that firms do not systematically err in their expectations. The expectations of firms of course depend on policy certainty. Policy uncertainty affects consumption and investment decisions in an adverse manner.

As a matter of fact, a recent IMF working paper on the situation of India provides partial support to the demand-led approach. They note: ‘Real interest rates account for only one quarter of the explained investment slowdown.’ For them, the key factor is policy uncertainty, but, the demand-led growth theorists, I think, will advocate the examination of the exact mechanisms through which monetary and/or fiscal policies have deterred investment. Without explaining further in this blog post, the answer might be found in the manner in which autonomous elements of demand such as autonomous consumption, research & development expenditures, government expenditures and foreign expenditures are affected by policy uncertainty. To conclude, it is time that the interest-elastic investment function is seriously questioned both on theoretical and empirical grounds, and subsequently discarded.

A Foreword to Keynes’s General Theory

Published in 1936, The General Theory of Employment Interest and Money remains a valuable book for both economists and policy makers. The recent financial crisis and the ongoing economic crisis have revived popular interest in this 1936 classic. The year 2009 saw the publication of two concise books on Keynes by two eminent scholars, Skidelsky and Clarke; an earlier blog post reviewed both their works. Not much will be said about the author – John Maynard Keynes, in the following paragraphs. The main objective of this blog post, as the title suggests, is to provide a foreword to The General Theory. By foreword, we mean the following: ‘The introduction to a literary work, usually stating its subject, purpose, scope, method, etc.’ (Oxford English Dictionary).

The rapidly expanding market for economics textbooks has, to a significant extent, substituted the reading of original works. In this environment, where our understanding of Keynes is based upon what Blanchard, Branson, Mankiw or Romer write, the following blog post strives to remain faithful to Keynes unlike the IS-LM version of Keynes proposed by Hicks and popularised by these textbooks. Keynes labelled Ricardo, Marshall and Pigou as Classical economists; this definition is not adhered to in the present blog post for Classical economics is a system of economic theory (to which Ricardo belongs) which is distinct from and a rival to Marginalist economics of which Marshall and Pigou are important members (see Thomas 2011 for more).

For Marshall, Pigou and marginalist economists of today, unemployment is a transitory phenomenon caused by ‘imperfections’ in the operation of the market forces. In their theoretical world characterised by competition, full employment is the ‘general’ case. However, Keynes demonstrated that this notion was based on assumptions contrary to the real world such as flexibility of money wages, absence of store of value function of money and rate of interest as a real phenomenon capable of equilibrating savings and investment and hence can only be considered a ‘special’ case. As he writes, ‘there has been a fundamental misunderstanding of how in this respect the economy in which we live actually works’ (p. 13). Opposed to this state of affairs, Keynes argued that the ‘general’ situation in an economy with competitive markets is the prevalence on unemployment. In other words, the central purpose of Keynes’s work is to demonstrate that unemployment is the usual situation in a competitive economy.

The main subject matter of The General Theory is the determination of aggregate employment and income or ‘the theory of output as a whole’ (Preface, p. vi). This needs to be seen against the then prevalent mode of economic analysis which was largely Marshallian in nature. Marginal productivity theory along with the principle of substitution was employed to understand the allocation of a given level of output; under conditions of competition, in equilibrium, full employment was (and still is) expected to prevail. And questions concerning the determination of the level of output were carried out within a theory whose primary subject matter was allocation, and not determination, of output levels. (On this, see especially Keynes’s preface to the German edition of his 1936 book.)

Marginalist economics, in the 1900s, looked up to the works of Marshall, and Pigou.  Keynes was brought up on a large dose of their works. Theories of production concentrated on determining the output levels in individual markets, and more often on allocation of output. Similarly, theories of distribution examined the allocation of income to workers and capitalists. Policy recommendations were made on the basis of such theories. The remedy to unemployment, according to Pigou and other orthodox economists, consisted in lowering workers’ wages. Economics certainly did not have an apparatus or a framework to study the ‘level of output as a whole’, or macroeconomics as it is called today. Besides output levels, Keynes also stressed the role played by money in ‘real’ analysis – the examination of income, employment, investment, consumption and saving. Rate of interest, according to Keynes, is a monetary phenomenon which depends on liquid preference. In short, the scope of his work remained the same as that of earlier economists – the study of wealth. Today, economics has broadened its scope to include any subject which can be examined by employing some form of the cost-benefit analysis. (See Malthus: The Scope of Political Economy)

Being brought up in the marginalist Marshallian tradition, Keynes attempted to completely break away from their method. In the preface to the German edition, he makes his desire explicit: ‘It was in this [Marshallian] atmosphere that I was brought up. I taught these doctrines myself and it is only within the last decade that I have been conscious of their insufficiency. In my own thought and development, therefore, this book represents a reaction, a transition away from the English classical (or orthodox) tradition.’ However, his attempt was not entirely successful. This is especially visible in his analysis of investment, where he develops the ‘marginal efficiency of capital’; much has been written on this in the context of the capital theory debates. The role he assigned to ‘expectations’ and the links to investment levels have been considered an improvement of the economists’ toolkit and consequently seen as an improvement in the capacity of economic theory to understand reality.

The aim of this blog post has been mainly to put The General Theory in the 1936 context, where Marshallian economics reigned supreme. Today, central governments, central banks and policy makers employ macroeconomic theory to understand the real world and to frame policies which increase output levels, stabilise prices and ensure financial stability. However, majority of these theories remain rooted in the orthodox tradition (variants of Marshall, Walras, Pigou and others resurface in the form of DSGE, New Classical macroeconomics or New Keynesian macroeconomics) which Keynes broke away from. Truly, The General Theory published in 1936 remains an economics classic, which is of enduring value to those who find terrible problems with the current orthodoxy!

Short Introductions to Keynes: Skidelsky vs Clarke

The recent global financial crisis has led to a renewed interest in the works of John Maynard Keynes. In part, this is motivated by the intellectual failure of contemporary economics and the search for important insights into the working of the real and financial sectors. Another part owes to the dissatisfaction with conventional economics and restoring the research programme of Keynes seems to point at a better alternative. Together, revisiting the works of Keynes does assume great importance in the current economic and political climate. Two books stand out in this regard: Robert Skidelsky’s Keynes: The Return of the Master and Peter Clarke’s Keynes: The Rise, Fall, and Return of the 20th Century’s Most Influential Economist. Both of them were published in 2009. This blog post is a critical examination of these two books.


According to Skidelsky, ‘the root cause of the present crisis lies in the intellectual failure of economics’ (p. xiv). To avoid such crises in the future, Skidelsky encourages economists to think of economics ‘as a moral, not natural, science’ (p. xvi). We are quite aware of the affinities between Malthus and Keynes, on the role of consumption. Besides this, Malthus had a similar vision of economics (political economy as it was known then) as Keynes. That is, Malthus also views economics as a ‘science of moral and politics’; For Keynes, economics is a ‘moral science . . . it deals with introspection and with values . . . it deals with motives, expectations, psychological uncertainties’ (p. 81). Keynes’s economics and broader ideas, argues Skidelsky, aids in contemporary economic thinking and policy making. In particular, the role of uncertainty is emphasised.

The intellectual stature of Keynes is something that is well-established. Skidelsky provides the readers with a statement from the philosopher, Bertrand Russell: ‘Keynes’s intellect was the sharpest and clearest I have ever known. When I argued with him, I felt that I took my life in my hands, and I seldom emerged without feeling something of a fool’ (p. 57). In any case, Keynes was extremely active in academic and policy discussions.

Keynes argues that investment is determined by expectations and depending on the state of confidence, investment would increase or decrease. This renders investment unstable, as a policy variable. In addition, if savings are greater than investment, it diverts resources ‘from the wider economy into financial speculation and conspicuous consumption’ (p. 69). Consumption is seen as the stable component of demand. Keynes also clarified the very important distinction between decisions to save and actual saving. Firstly, ‘If everyone wants to save more, firms will sell less and therefore output will fall, unless the inducement to invest is increasing at the same time (p. 91). This is the paradox of thrift, a simple enough idea but very powerful which had not been presented clearly so far. Therefore, if increases in saving are not matched by increases in investment, it will cause a fall in output and employment. In short, ‘It is spending, not saving, which creates output and employment; and when spending falls short of earnings, unemployment results’ (p. 91). Skidelsky captures the most important conclusion of Keynes’s General Theory which is ‘that a decentralized market economy lacks any gravitational pull towards full employment’ (p. 97).

So far, so good. However, when it comes to Keynes’s views on classical economics, Skidelsky falls prey to the conventional view. The conventional view being that Keynes attempted to disprove the economic theories of classical economissts such as Smith, Ricardo and Malthus. This view is far from the reality. (For a concise account of this, see my short article in the DSE Journal.) In fact, Skidelsky, being very faithful to Keynes’s words calls Arthur Pigou a classical economist (see p. 104). Suffice it to say here that classical economists such as Smith, Ricardo and Malthus maintained that unemployment could be a permanent feature of capitalistic economies. By classical economists, Keynes actually meant the (neoclassical) economics of Marshall and Pigou. In the following paragraphs, we will see that Clarke deals with this issue in a more satisfying way.


We need to read Keynes today, says Clarke, because of his ‘lifelong commitment to the strategy of institutional reform through reasoned argument’ (p. 23). This means that we need to understand the historic and political context in which he lived. Also, reading ‘Keynesian economics’ is no substitute for understanding Keynes. In fact, as Clarke informs us: ‘After dining with a group of American Keynesian economists in Washington, DC, in 1944, Keynes said at breakfast the next morning: ‘I was the only non-Keynesian there’’ (p. 168).

Similar in spirit to Brtrand Russells’ comment, Clarke shares with us that ‘Friedrich von Hayek, Keynes’s most formidable academic opponent, wrote that ‘he was the one really great man I ever knew, and for whom I felt admiration’’ (p. 10). Clarke sheds light on the not often discussed aspect of Keynes’s life – his training in economics. Alfred Marshall, Keynes’s family friend, taught economics to Keynes. ‘It was the usual Cambridge system of individual supervision, one hour a week for the eight weeks of the teaching term – the only formal instruction in economics that Keynes ever received’ (pp. 24-25). In any case, this doesn’t matter and clearly, it didn’t matter. For him, economic theory was not an end in itself (like the classical economists). ‘The whole point lies in applying them to the interpretation of current economic life’ (p. 49). In this quest, there are no roles for dogmas. Hence, he expressed his dissatisfaction with both anti-capitalist as well as free trade dogmas. However, the latter emerged as his primary target (p. 68). On the free trade system, Keynes writes the following: ‘It is not intelligent, it is not beautiful, it is not just, it is not virtuous – and it doesn’t deliver the goods’ (p. 72). To this end, by writing the General Theory, Keynes wanted to change the thinking of economists first and foremost. This is why the General Theory is ‘a concentrated assault on inside opinion as the necessary prelude to converting outside opinion’ (p. 77). Given those difficult times, the theoretical and policy oriented intervention of Keynes was essential. For, ‘Many people [were] trying to solve the problem of unemployment with a theory which is based on the assumption that there is no unemployment’ (p. 148).

We have already pointed the crucial distinction between saving and investment. Clarke puts forth the importance more clearly. ‘At the time, saving remained prized and honoured as the key to economic recovery. Keynes’s serious point is to distinguish saving (or thrift), which is essentially negative, from the real motor of economic growth, investment (or enterprise)’ (p. 106). Furthermore, Keynes is correct when he states: ‘I think it makes a revolution in the mind when you think clearly of the distinction between saving and investment’ (p. 107). Too much saving diminishes income. ‘It is a paradox because it seems natural to suppose that if individual saving enriches the individual concerned, it must also enrich the community’ (p. 152). Despite these crucial differences between saving and investment, much of the modern theories of economic growth seems to take the equality for granted; thanks to the single-good models and continuous production functions.

The commentary by Clarke on Keynes’s view of classical economics is historically accurate and therefore more satisfying than that of Skidelsky. The following extracts bear testimony to this. ‘Keynes later took him [Pigou] as representative of the ‘classical school’, devoting seven pages of the General Theory to a demolition of Pigou’s The Theory of Unemployment (1933)’ (p. 108). ‘Orthodox economics assumed that the system reached its own equilibrium through the effect of interest rates in reconciling the level of investment to the amount of saving available – through flexible prices, of course’ (p. 131). ‘‘Classical’ economics – really Marshallian orthodoxy – said an infinitely adjustable price mechanism will deliver equilibrium via interest rates’ (p. 134). Finally, Keynes’ friend and a reviver of classical economics, Piero Sraffa, is said to have brought the terms ‘effective demand’ to the attention of Keynes. ‘Keynes decided to salute Malthus as yet another brave Cambridge pioneer by purloining his term ‘effective demand’ to describe his own theory of output as a whole’ (pp. 143-4).

Concluding thoughts

The two introductory books on Keynes by Clarke and Skidelsky attest to the intellectual and practical relevance of his work. A few points are in order. First, a perfectly competitive economy does not have intrinsic forces that result in full employment. Secondly, saving and investment are conceptually distinct variables. Finally, economic theory is a means to understanding contemporary society and not an end in itself. I let Clarke have the last word: ‘Keynes’s name is thus rightly invoked to license fresh approaches to the novel economic difficulties of our own era – to tackle them actively rather than take refuge in inert doctrinal purity’ (p. 180).

Pierangelo Garegnani (1930 – 2011)

On October 14, 2011, heterodox economics (in particular, classical economics) lost one of its warriors. This post attempts to summarise some of his key contributions towards economic theory. First and foremost, he was an economic theorist par excellence. He contributed to the famous (now, almost forgotten) capital theory debates in 1960s along with Piero Sraffa and Joan Robinson on his side and Paul Samuelson and Robert Solow on the other. Alongside others, he pointed out logical flaws in the marginalist conception of capital and its devastating effects on equilibrium. Basically, marginalist theory of value and distribution (in modern parlance, microeconomic theory) was shown to be logically inconsistent. Today, these debates hardly ever appear in economics textbooks because marginalist or neoclassical economics invented inter-temporal equilibrium to take care of capital-theoretic issues. Moreover, history of economic thought has been sidelined – through famous graduate economic programs and by preaching that history of economic thought is of no use to a “practical” economist, both in academia and in business.

Garegnani made significant contributions to the revival of classical economics on the foundations laid down by Piero Sraffa. In particular, Garegnani, through various journal articles (in Italian and English) resurrected the works of old classical economists – mainly Smith, Ricardo and Marx. More than Sraffa, perhaps, it is Garegnani who has aided the revival and resurrection of classical economics. His command over the history of economic thought with a special focus on old classical economists and ‘old’ and ‘new’ neoclassical economists (Walras, Wicksell, Hicks, etc) is evident from his clear exposition of their analytical structure.

Like ‘old’ classical economists, Garegnani’s interest has been to explain growth dynamics of an economy. This, he believed and also demonstrated that it is possible by drawing insights from Keynes and working on a classical (Sraffian) foundation. In this regard, Garegnani and his friends-colleagues-students have been quite successful in their analysis of capacity utilization, supermultiplier, role of wages, profits being a monetary phenomenon and so on.

Given the massive contributions made by Garegnani, it has been an honour for me to have been introduced to his work during my Masters in Economics at University of Hyderabad. It is one of the few Universities, in India and possibly, in the world, which still teaches classical economics as a distinct approach to understanding contemporary economies. I hope that more Universities begin to recognise the benefits of a pluralist education and start teaching classical economics as a distinct subject.


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