Revisiting J. H. Clapham’s ‘Empty Economic Boxes’

This blog post revisits the economic historian J. H. Clapham’s1922 classic paper ‘Of Empty Economic Boxes‘ published in The Economic Journal, and raises some critical questions about the continued use of constant returns to scale (CRS hereafter) assumption in marginalist (or neoclassical) microeconomics and macroeconomics. In 1926, Piero Sraffa took Clapham’s 1922 paper as a starting point to mount a more devastating logical critique of Marshallian notions of increasing returns and the representative firm; this was published as part of a symposium in the Economic Journal.

What is returns to scale’ According to marginalist economics, the technique of producing a commodity may be represented by a functional relationship between inputs (say, k’and l) and output (say, y): y’= f(k,l). If all the inputs are multiplied by a positive scalar m, and the resultant output is expressed as mr’y, then r’represents the magnitude of the returns to scale. If r = 1, the technique exhibits CRS, if r < 1, it exhibits diminishing returns to scale (DRS), and if r’> 1, it exhibits increasing returns to scale (IRS).

Despite the ‘advances’ in mainstream economics research, the marginalist theory of value and distribution still requires the CRS assumption (and the diminishing returns to a factor assumption) to make several key claims. The aggregate production function employed in the Solow growth model is assumed to exhibit CRS. And the Solow growth model forms the core of supply-sidegrowth accounting exercises which are used to make policy prescriptions (for a critique of one such exercise for the Indian economy, see Joshi & Thomas 2013).

The central argument in Clapham’s article is that the categories of diminishing returns, constant returns, and increasing returns industries are ’empty economic boxes’. In other words, from the standpoint of actual economies, these categories lack empirical and historical content. Consequently, industries cannot be classified into one or the other box a priori.

Clapham asks: what does AC Pigou (in his Economics of Welfare) mean when he writes ‘when conditions of diminishing returns prevail’ (p. 305)’ According to Clapham ‘constant returns…must always remain a mathematical point, their box an empty one’ (p. 310). He acknowledges that different kinds of returns have a ‘logical’ and ‘pedagogic value’ which ‘goes so prettily into graphs and equations’ (p. 312). How can we then use this framework to draw policy conclusions given the inability to classify industries a priori into constant, diminishing, and increasing returns’

The following observation by Clapham is insightful and worth thinking about further. He writes that diminishing returns must be balanced with increasing returns to arrive at constant returns (p. 309). Surely, this makes no conceptual sense and neither does it have any basis in empirical reality. As Clapham puts it, with CRS ‘the conception of the balance of forces, man’s organization versusNature’s reluctance, was worked out’ (p. 309). In other words, is CRS an expression of the balancing of the symmetrical forces of IRS (‘man’s organization’) and DRS (‘Nature’s reluctance’)’ For a visual representation, see the images below. If so, it would add to the symmetrical concepts found in the marginalist toolbox, most notably that of supply and demand. However, beyond the ease of exposition symmetry provides us, is it really how the actual world works’


CRS, DRS, and IRS posit an a priori functional relationship between labour (L) and capital (K), the ‘factors of production’ and output (Y) for an individual firm and for an economy: Y=f(L,K). While the idea underlying the production function, whether industry-level or aggregate-level, that outputs are produced by inputs is commonsensical and intuitive, its expression as a mathematical function isn’t as benign. Since marginalist economics requires continuous functions (often, of a monotonic nature) to ensure the existence of equilibrium, the ‘f’ is able to map infinitesimal combinations of Land Kto a unique Y. This ‘one-way street’, to use Sraffa’s phrase in his 1960 classic Production of Commodities by Means of Commodities(see my blog post Sraffa), between ‘factors of production’ and output is conceptually unsatisfactory because it misses a fundamental aspect about modern economies: the structural interdependence between inputs and outputs. In addition, it assumes that capital goods (K) are infinitely divisible, a very difficult assumption to uphold.

John Eatwell (2008; first published in 1987), in his entry on ‘returns to scale’ published in The New Palgrave Dictionary of Economics, also notes the apparent symmetry between IRS and DRS but points out its spuriousness. While there is no evidence of functional relationships in Adam Smith and David Ricardo, Smith’s discussion of division of labour, capital accumulation, and economic growth indicates that he recognised scale-enabled technological progress and Ricardo recognised diminishing returns to land, a non-reproducible input in production. Subsequently, Alfred Marshall, in his Principles of Economics, ‘attempted to formulate a unified, symmetric, analysis of returns to scale which would provide the rationale for the construction of the supply curve of a competitive industry, derived in turn from the equilibria of the firms within the industry’ (Eatwell 2008, p. 140). This point was initially noted by Sraffa 1926, and later much more thoroughly investigated also by Krishna Bharadwaj (1978).

It is well understood that the question of returns to scale is important in the construction of the supply curves which are integral for the marginalist price theory. Therefore, a thorough critical study of mainstream price theory and a renewal in the interest in rival price theories (found in Ricardo, Marx, Sraffa, and Kalecki, among others) are warranted. This is crucial because it is value or price theory which provides us with the economic possibilities a competitive economy generates. If it generates unemployment and worsens inequality, we know that intervention of a particular kind is necessary. However, if it generates full employment and reduces inequality, then it supports the idea of making markets more competitive and reducing government intervention.


Clapham, J. H. (1922), “Of Empty Economic Boxes.”‘The Economic Journal,’vol. 32, no. 127, pp. 305-14.

Eatwell, John (2008), ‘Returns to Scale’. In: Durlauf S.N., Blume L.E. (eds.) The New Palgrave Dictionary of Economics. London: Palgrave Macmillan.

Sraffa, Piero (1926), “The Laws of Returns under Competitive Conditions.”‘The Economic Journal,’vol. 36, no. 144, pp. 535-50.


I thank Mohib Ali for his helpful comments.


A Case for Pluralism in ‘Microeconomics’

[My return to blogging is motivated by the extremely warm response I’ve received in person – in the last 6 months – from several people who have been readers of this blog. I’m also happy to announce the publication of my co-edited book on the history of economic thought.]

The subject matter of microeconomics is enshrined in the economics curriculum at all levels – school, undergraduate, postgraduate, and doctoral. The central objective of microeconomic theory is to provide a solution for equilibrium price and quantity in both the commodity (say, apples or coconuts) and factor (wage and ‘capital’) markets. Indeed, questions of what is the source of value and what is the exchange value of two commodities have been posed much earlier. You can find answers in Kautilya, Aquinas, Petty, and Cantillon – all of them writing prior to Adam Smith’s foundational treatise on political economy.


Kautilya’s Arthashastra contains discussions of a fair price. Aquinas, drawing inspiration from Aristotle and Christianity, tries to arrive at the notion of a just price. One of the founders of political economy, William Petty, derives the distinction between necessary price and political price and possesses a rudimentary labour theory of value. Following Petty, Cantillon distinguishes between ‘intrinsic value’ and ‘market price’ based on a land-cum-labour theory of value. The contributions of Smith, Ricardo, Marx, and Sraffa to value theory follow this tradition of objectively determining value.


The dominant theory of value in contemporary economics is not the objective theories of value found in Ricardo, Marx, or Sraffa but the subjective theories of value whose pioneers are Jeremy Bentham, William Stanley Jevons (whose son taught at Allahabad University), Alfred Marshall, AC Pigou, and Paul Samuelson. The value theory (or microeconomic theory, as it is now called more fashionably) found in the textbooks of Hal Varian or Gregory Mankiw take the following as data when solving for equilibrium prices and quantity: (i) preferences, (ii) technology, and (iii) endowments. On the other hand, Piero Sraffa’s value theory, found in his Production of Commodities by Means of Commodities (1960), takes the following as given when arriving at a solution for prices and one distributive variable: (i) size and composition of output, (ii) technology, (iii) the real wage or rate of profit.


How do you measure the data listed above’ While technology, endowments, and real wage can be measured in terms of the commodity-mix, the rate of profit is a pure number. However, how are preferences measured (or ordered)’ They are measured in a subjective manner. This is one of the core differences between the dominant marginalist theory of value and the Classical/Sraffian objective theory of value. Given this core difference, it is incorrect to treat the objective theory of value found in Ricardo or Marx as a precursor or rudimentary version of modern subjective theory of value. And therefore, it is important that students of economics learn about different value theories in microeconomics.


I shall end by drawing your attention to the practical implications of believing in the marginalist conception of the labour market vis-a-vis that of the classical economists (see an earlier post on wages). Under conditions of perfect competition, the equilibrium real wage is determined by the marginal product of labour. Any intervention, such as a minimum wage legislation or collective bargaining by the workers, results in imperfections and consequently leads to unemployment. However, in classical economics, real wage is exogenously determined though historical and social factors. If you believe in the marginalist conception, the logical policy recommendation is to eliminate any intervention/imperfection (such as minimum wage legislation or collective wage bargaining) whereas if you believe in the classical conception, you would treat collective wage bargaining and minimum legislation as legitimate ways of improving workers’ conditions.


This post argues that value theory matters for both contemporary politics and policy. And consequently, the teaching of microeconomics needs to become pluralistic. Moreover, as pointed out earlier, the politics of microeconomics ought to be made explicit. It is, as Keynes, said that we are the ‘usually the slaves of some defunct economist.”


Kunkel on David Harvey and Robert Brenner: Demand, Profits and Employment

The link between demand and profits, and consequently employment, is visible in the works of the classical economists and Marx. In this blog post, we set out the link between these variables by way of assessing the contributions of David Harvey and Robert Brenner, as narrated and presented by Benjamin Kunkel in his 2014 collection of essays, all previously published ‘ Utopia or Bust: A Guide to the Recent Crisis (and not on the basis of Harvey’s and Brenner’s original texts).

Karl Marx has already presented us with the possible reasons for the occurrence of crises in capitalist economies. Kunkel treats these crises as profitability crises (pp. 34-6); they can occur because of (1) profit squeeze, (2) a rising organic composition of capital, and (3) underconsumption. A capitalist crisis causes activity levels to drop and results in wide-spread unemployment. The three factors mentioned above reduce the profits of capitalists, consequently affecting their decision to produce and therefore adversely affecting their decisions to employ workers and purchase capital goods. The first ‘ a profit squeeze, is self-explanatory, but its causes need not be. A rise in real wages, ceteris paribus, leads to a decline in the rate of profit. The organic composition of capital, according to Marx, refers to the ratio between constant capital and variable capital. Constant capital refers to the investment expenditure on plant, machinery, tools and other constant/fixed capital. Variable capital refers to the investment expenditure relating to the workers ‘ wage costs, training costs and the like. When the ratio of constant to variable capital rises, or equivalently, when the organic composition of capital rises, the rate of profit (the ratio between profits and capital advanced) falls. The third cause is underconsumption, by workers. This occurs, by definition, since the value of the real wage is less than the value they add to the commodity. In Marxian terms, this difference measures the surplus-value that the capitalists extract from the workers.


Strong bargaining power on the side of the workers can generate a rise in the real wages; although, note that the terms of agreement are usually set in money wages. The rising organic composition of capital is not a law, but a contingent proposition. As for underconsumption, if workers’ wages are just sufficient for their survival, it can result in goods lying unsold and therefore affect capitalist profits. To put it differently, there arises a gap between aggregate supply and aggregate demand. This, according to Harvey, places a ‘limit to capital’.

What can possibly eliminate underconsumption, a facet of capitalism, a consequence of positive capitalist profits and a cause of economic crisis’ Harvey points out that it is credit which eliminates this cause, at least, temporarily.

‘Any increase in the flow of credit to housing construction, for example, is of little avail today without a parallel increase in the flow of mortgage finance to facilitate housing purchases. Credit can be used to accelerate production and consumption simultaneously.’

(Harvey; as quoted on p. 32)

But, Kunkel cautions us that even if credit can fund the required aggregate demand, changes in income distribution brought about by the struggle between workers and capitalists will affect the aggregate equilibrium, and will render it unstable.

‘If there exists a theoretical possibility of attaining an ideal proportion, from the standpoint of balanced growth, between the amount of total social income to be reinvested in production and the amount to be spent on consumption, and if at the same time the credit system could serve to maintain this ratio of profits to wages in perpetuity, the antagonistic nature of class society nevertheless prevents such a balance from being struck except occasionally and by accident, to be immediately upset by any advantage gained by labor or, more likely, by capital.’ (p. 37)

It is not entirely clear what mechanisms and processes Kunkel is referring to when he makes the above claim about income distribution rendering the equilibrium unstable. Indeed, if the available credit is not sufficient to counter the depressed wages and high profits, the aggregate equilibrium will be unstable.

Another route through which capitalist crisis can be postponed is via long-term infrastructural projects. ‘Overaccumulated capital, whether originating as income from production or as the bank overdrafts that unleash fictitious values, can put off any immediate crisis of profitability by being drawn off into long-term infrastructural projects, in an operation Harvey calls a ‘spatio-temporal fix” (p. 39). Here again, it is contingent on the extent to which the workers gain from the surplus generated by these projects, both in the short and long-term. For example, the employment guarantee programme in India creates infrastructure as well as provides employment and wage income.

‘So what then are the ‘limits to capital” (p. 41)’ ‘Keynesians complain of an insufficiency of aggregate demand, restraining investment. The Marxist will simply add that this bespeaks inadequate wages, in the index of a class struggle going the way of owners rather than workers’ (p. 43). Inadequate wages, as previously indicated, does generate demand deficiency. To that extent, Marx’s and Keynes’s account of capitalist crises are very similar.

Kunkel points out the role of environmental degradation, a consequence of capitalist drive for profits, in capitalist crises. ‘Already three-concentrations of carbon in the atmosphere, loss of nitrogen from the soil, and the overall extinction rate for nonhuman species-have been exceeded. There are impediments to endless capital accumulation that future crisis theories will have to reckon with.’ This can be easily integrated into the theories of output and of growth, as Ricardo’s diminishing returns to land, has been. Environmental depletion poses constraints on the supply side primarily and for economic growth, positive capital accumulation is necessary. Therefore, environmental degradation poses a strong constraint on the supply side of the economy.


Robert Brenner made a ‘frontal attack on the idea of wage-induced profit squeeze’ (p. 87). As Kunkel puts it, ‘increased competition exerted relentless downward pressure on profits, resulting in diminished business investment, reduced payrolls, and-with lower R&D expenditure-declining productivity gains from technological advance. The textbook result of this industrial tournament would have been the elimination of less competitive firms. But the picture drawn by The Economics of Global Turbulence is one of ‘excessive entry and insufficient exit’ in manufacturing’ (p. 87). In other words, the profit squeeze was not wage-induced.

Marx’s realization crisis finds a mention in Kunkel’s essay on Brenner too. ‘If would-be purchasers are held back by low wages, then the total mass of commodities cannot be unloaded at the desired price. Capital fails to realize its customary profits, and accumulation towards stagnation’ (p. 91). This is the crucial point. Capital has to realize its customary profits, a magnitude which includes a return on risk and undertaking (a return on enterprise, if you like) and the rate of interest. Capital that is invested in a riskier enterprise is expected to provide higher returns. The search for demand (or markets) is not new. Mercantilism was precisely that. More recently, ‘[i]n Germany and Japan, and then in China, catering to external markets won out over nurturing internal demand’ (p. 94) However, currently, there are signs of a reversal as external demand is falling, and net-exporting countries are reorienting towards domestic demand (p. 95).

But, what is to be done’ According to Kunkel, ‘[g]lobal prosperity will come about not through further concessions from labor, or the elimination of industrial overcapacity by widespread bankruptcy, but through the development of societies in which people can afford to consume more of what they produce, and produce more with the entire labor force at work’ (p. 98). Kunkel rightly advocates better wages and the full-employment of labour. For, it is only such a society which can afford its citizens with a dignified and economically comfortable life. As a matter of fact, ‘[m]ore leisure or free time, not less, would be one natural-and desirable-consequence of having more jobs’ (p. 103). A similar call is visible in Robert & Edward Skidelsky’s How Much is Enough’ Money and the Good Life published in 2012. We urgently need an economic architecture where goods can flow easily across regions, workers earn good wages, capital earns its customary profits, labour is fully employed and the environment is respected. In working towards this goal, it is necessary to possess an accurate understanding of the link between demand, profits and employment.

Prices, Competition and Markets

It has become commonplace in India to point fingers at the central government when prices of essential commodities such as onion or fuel rise. The underlying arguments behind this accusation could be that: (1) the government is expected to maintain price stability and/or (2) the government should socially engineer agricultural markets in a ‘fair’ manner. But, is the pursuit of price stability not the job of the Reserve Bank of India (RBI)’ It is true that the RBI cannot do anything to combat inflation when it is caused by a supply-and-demand mismatch in the domestic vegetable market or the international oil market. What the RBI can do is manage inflation expectations, and that is for another post. The present post is motivated by the insightful analyses of Kannan Kasturi on the Indian vegetable market, published in the Economic & Political Weekly and other places. That is, this post takes up the second of the reasons mentioned earlier.

The price mechanism ‘ adjustments made by producers to the selling prices and consumers to the purchasing prices ‘ is expected to allocate the commodities brought to the market amongst the consumers, in accordance with their needs, reflected in their willingness to pay. The prices therefore act as signals for the producers especially. Sellers can adjust quantity in order to affect prices; hoarding commodities is one such strategy. At equilibrium, producers earn a normal rate of profit, which contains a pure rate of return on capital advanced and a return for risk and entrepreneurship. If producers do not make normal profits in time t, they will cut down production in time t+1. During the equilibration process, producers who are unable to earn a normal rate of profit will exit the market. If entry costs are low, new producers will enter the market. Producers who have large financial resources (or access to easy credit) at their disposal are insulated from temporary alterations in demand. Producers who have enough accumulated earnings can shield themselves from such market volatility. In short, a competitive market is one where prices are not distorted (by the producers or by external intervention), no (especially, cultural and social) barriers to enter the market exist and workers are mobile within and across markets.

Of course, the agricultural markets in India are far from competitive. Since more than 50% of Indians derive their income from agriculture, and particularly because of the poverty of the farmers, these markets require government intervention. This is not to say that any form of government intervention will better the situation. Kasturi quite convincingly shows that the fault lies with the supply-side ‘ the agricultural supply chain. This post will not discuss minimum support prices or other input subsidies, such as for electricity, irrigation and fertilizers. Also to be noted is the specific manner in which the agricultural input markets are inter-linked in India, which has been of an exploitative nature. Finally, social and cultural factors (pertaining to caste and gender) are seen to hinder competitiveness in Indian markets, not just in agriculture.

What are the problems with the agricultural supply chain’ Kasturi points out the following: (1) Small farmers lack storage facilities in order to gain from the high market prices. (2) The middlemen (those who intermediate between farmers and final consumers), i.e. the wholesale traders and commission agents have the ability to hoard vegetables and consequently they reap the benefits of the high prices they themselves engineer; the Agricultural Produce Marketing Act governs the agricultural markets (mandis) and it is here where all the proceeds from higher prices are absorbed with nothing reaching the farmers. These traders and commission agents are ‘well entrenched in the mandis, having been in the business on average for 20 years’ (3) Agricultural pricing is not at all transparent and the mandi records are of no assistance in this regard.

To sum up, the nature of government intervention has to change, in such a way that is beneficial to farmers. Proper laws are of utmost importance, not just in protecting the interests of the small farmers, but also that of the consumers. ‘Moreover, intermediaries in any market perform useful functions but laws should be in place which ensures that they do not become monopolistic and exploitative. Agricultural infrastructure such as storage facilities is paramount in this context. A very detailed study of how these supply-chains operate will be of much help in our attempts to combat inflation.