Wednesday, March 17, 2010

Kaldor's Model of Industry and Agriculture

In comments, an anonymous poster asks:
Is the Kaldorian model on industrial and General productivity in an economy applicable in understanding economic development in LDC's like Zambia?
I don't know anything about Zambia.

As I understand it, Kaldor developed that model for the world as a whole. Thirlwall applied that model to a Less Developed Country in a 1986 paper.

In the model, labor is originally not scarce - there is disguised unemployment in agriculture. Industrial production, unlike in agriculture, experiences increasing returns. If wages are low in agriculture, there would be more savings to finance expansion of industry. But there might not be the demand for industrial products. Demand for industrial products is increased by a relatively low price of industrial products, as compared to the price of agricultural products. Demand for industrial commodities might also be for exports. A dynamic equilibirum arises in the model in which a steady state of growth is achieved and the terms of trade between agriculture and industry are specified. The model is supposed to capture certain stylized facts and exhibit a certain complementarity between agriculture and industry. It is also supposed suggest different possibilities, such as the possibility of economic development from favorable terms of trade for agriculture at an initial stage and export-oriented growth at a later stage.

Later essays in Thirlwall's book in which his essays was reprinted treat Africa, particularly the Sudan. This empirical work treats some other considerations than those included in the mathematical outlined verbally above. I don't know current thinking about these issues, although I question the thinking that had been dominant in the Internation Monetary Fund, that is, the "Washington consensus".

  • A. P. Thirlwall (1986) "A General Model of Growth and Development on Kaldorian Lines", Oxford Economic Papers (July) (Reprinted in The Economics of Growth and Development: Selected Essays of A. P. Thirlwall, Edward Elgar (1995))

Friday, March 12, 2010

Anti-Intellectualism Among Mainstream Economists

I find these comments to be anti-intellectual:
  • John Quiggin rejects the Austrian school of economics on the ground that partisans of that school discuss political philosophy and the epistemology and methodology of economics.
  • Roberto Perotti critizes Post Keynesians and neo-Ricardians on the grounds that they don't spend their time exclusively constructing formal models and estimating correlations. (I used Google's translation feature. Sergio Cesaratto answers from a Sraffian perspective.)
  • Commentators at Mark Thoma reject discussions about what Adam Smith wrote.
I thought the point of scholarship was to attempt to make true statements. If somebody makes an untrue statement about what Keynes or Adam Smith said, one should correct them. This is not to say that that the fact that Keynes or Smith advocated something or other is a justification for policy. I think a historically accurate representation of an old text entails quite a bit of contextualization in terms of its time. To apply policy conclusions to our time would require recontextualization in contemporary terms, as well as empirical work.

I would think different scholars, even within a discipline, would find different questions of interest. Some economists argue for a supposed freedom to choose. Shouldn't some then be legitimately allowed to explore old texts or methodology or whatever? If Thomas Kuhn was somewhat correct, wouldn't one expect more discussion about methodology when the defining paradigm in a field has so obviously broken down, as today among mainstream economists?

Thursday, March 11, 2010

On Sraffa, Elsewhere

Alex M. Thomas has begun a series of posts about Piero Sraffa's work in economics.

Saturday, March 06, 2010

Survey of Utility Theory?

1.0 Introduction
I think utility theory has a canonical textbook presentation. Many variations seem to exist. In some, the additional structure is imposed on the (commodity?) space over which agents choose. In others, more basic assumptions are made from which preferences can be derived under certain special cases.

I'd like to know if there are any surveys to read over these variations. I'm not insisting on something critical. And, given the dryness of the subject matter, I might not put such a survey on top of my queue. As can be seen below, I'm not sure of the field that would be demarcated by such a surveys. But literature surveys, in some sense, construct their object.

2.0 Textbook Treatment
Consider a space of n commodities. Each element of the space is a vector x = (x1, x2, ..., xn). Under the usual interpretation, xi is the quantity of the ith commodity.

An agent is modeled as having a preference relation, ≤, over the space of commodities. A typical question is what assumptions must hold for a utility function to exist. A utility function u(x) exists if, for all x and y in the space of commodities:
xy if and only if u(x) ≤ u(y)

Typically, the preference relation is taken to be a total order, that is, complete, reflexive, and transitive. A preference relation is complete if, for all x and y in the space of commodities,
xy or yx
A preference relation is reflexive if, for all x in the space of commodities
xx
A preference relation is transitive if, for all x, y, and z in the space of commodities,
if xy and yz then xz

If the quantities of commodities fall along a continuum, a preference relation being a total order is not sufficient for a utility function to exist. Lexicographic preferences are an example of a preference relation for which a utility function does not exist. A continuity assumption rules out this case. This assumption is that for all x in the space of commodities, the sets {y | yx} and {z | xz} of commodities not preferred to x and commodities x is not preferred to, respectively, are closed.

Theorem: If a preference relation is a total order and is continuous in the above sense, then a utility function exists.

The utility function is only defined up to a monotonically increasing transformation. In other words, utility is ordinal. Typical exercises are to show certain properties of utility functions, such as ratios of marginal utilities (du/dxi)/(du/dxj), are invariant over the set of such transformations.

3.0 Probability
Von Neumann and Morgenstern generalized the commodity space to include vectors of the form: (p1, x(1); p2, x(2); ..., pm, x(m)), where:
p1 + p2 + ... + pm = 1
A commodity, in this sense, is a lottery. Each superscripted commodity vector x(i) is associated with a probability pi that it will be chosen.

Von Neumann and Morgenstern defined a new set of axioms to go along with their redefined commodity space. One implication is that for any two elements x and y in the commodity space, the linear combination (p, x; (1 - p), y) is also in the space. They obtain that a utility function exists, and it acts like mathematical expectation:
u(p1, x(1); p2, x(2); ..., pm, x(m)) = p1 u(x(1)) + p2 u(x(2)) + ... + pm u(x(m))

Under Von Neumann and Morgenstern's approach, utility functions are only defined up to affine transformations. That is, they are cardinal. In other words, they attain an interval measurement scale level. The utility for a lottery depends only on the probabilities and the resulting outcomes. It does not depend on how many spins of the wheel or roll of the dice are needed to decide between otherwise equivalent lotteries. Gambling is assumed to have no utility or disutility.

Leonard Savage develops axioms of probability concurrently with axioms of utility theory in his personalistic approach to probability and statistics. I'm not sure how much the survey I would like would go into approaches to probability, even if probability is important to decision theory. The same comment applies to game theory.

4.0 Attributes and Needs
Some see commodities as being chosen as an indirect means to choose something more abstract. As I understand it, Kevin Lancaster depicts a commodity as a bundle of attributes. Different commodities can have some attributes in common. A choice of an element in the space of commodities can then be related to an element in a space of commodity attributes.

The early Austrian school economists thought of goods as being desired for the satisfactions of wants. Water, for example, can be used to water your lawn, to satisfy a pet's thirst, or to drink yourself. One can imagine ranking wants in disparate categories. I am thinking of the triangular tables in Chapter III of Carl Menger's Principles of Economics, in Book III, Part A, Chapter III of Eugen von Böhm-Bawerk's Positive Theory of Capital, and in Chapter IV of William Smart's An Introduction to the Theory of Value. The tables are triangular because the most pressing want in one category typically is less pressing than the most pressing want in another category. An element in the space of commodities corresponds to the set of wants that the agent would choose to satisfy with the quantities of commodities specified by that element.

This mapping from quantities of commodities to sets of wants leads to a redefinition of marginal utility, which one might as well designate by a new name - marginal use. The marginal use of a quantity of commodity is, roughly, the different wants that would be added, with a set union, to the set of wants satisfied by the the given quantities of commodities with that additional quantity of the given commodity. McCulloch shows that a ranking of wants in different categories can arise such that a measure does not exist for the space of sets of wants. (A measure in this sense is a technical term in mathematics, typically taught in courses in analysis or advanced courses in the theory of probability.) He argues that the Austrian theory of the marginal use is thus ordinal. Surprisingly, his argument implies that the law of diminishing marginal utility does not require utility to be measured on a cardinal scale.

I haven't read Ian Steedman's work on consumption, but I think I'll mention it here.

5.0 Choices from Menus
Another generalization of the textbook treatment is to examine how a preference relation can be built out of a more fundamental structure. Imagine the agent is presented with a menu, where a menu is a nonempty set of elements of the commodity space. The agent is assumed to have a choice function, which maps each menu to the set of best choices, in some sense, in that menu. The agent is not postulated to rank either the elements not chosen for a given menu or the elements in the choice set.

A question: what constraints need to be put on choices out of menus such that preferences exist? Since a choice function can be constructed for which no preference function exists, some such constraints exist. I previously noted literature drawing on the logical structure of social choice theory in this context. Alan Isaac emphasizes temporal and menu independence in his overview of abstract choice theory.

6.0 Experimental Economics
I am emphasizing theory. A literature exists on experiments, many of which have falsified the textbook treatment of economics.

7.0 Computatibility, Conservation Laws, Etc.
Some of the above extensions of the textbook treatment seem to postulate some sort of structure within the agent's mind. Computers provide an arguable metaphor of mental processes, and some literature applies the theory of computability to economics. Gerald Kramer, for example, shows that no finite automaton can maximize utility in the simplest setting. I gather others have shown that the textbook treatment postulates that each agent's computation powers exceed those of a Turing machine, that agents compute functions that are, in fact, noncomputable. I turn to Kumaraswamy Velupillai's work for insights into computability, constructive mathematics, and economics. Philip Mirowski is always entertaining. One might also mention the literature on Herbert Simon's notion of satisficing

8.0 Conclusion
This post is a brief overview of some of what would be treated in a survey of variations and approaches to utility theory. Apparently, the notion of economic man can be complicated.

An Incomplete List of References
  • Colin F. Camerer (2007) "Neuroeconomics: Using Neuroscience to Make Economic Predictions", Economic Journal, V. 117 (March): C26-C42.
  • Alan G. Isaac (1998) "The Structure of Neoclassical Consumer Theory"
  • Daniel Kahneman and Amos Tversky (1979) "Prospect Theory: An Analysis of Decision under Risk" Econometrica, V. 47, N. 2 (March): pp. 263-292
  • Gerald H. Kramer () "An Impossibility Result Concerning the Theory of Decision-Making", Cowles Foundation Paper 274
  • Kevin J. Lancaster (1966) "A New Approach to Consumer Theory", Journal of Political Economy, V. 75: pp. 132-157.
  • J. Huston McCulloch (1977) "The Austrian Theory of the Marginal Use and of Ordinal Marginal Utility", Journal of Economics, V. 37, N. 3-4: pp. 249-280.
  • Judea Pearl (1988) Probabilistic Reasoning in Intelligent Systems: Networks of Plausible Inference, Morgan Kaufmann
  • Leonard J. Savage (1954, 1972) The Foundations of Statistics, Dover Publications
  • Chris Starmer (1999) "Experimental Economics: Hard Science or Wasteful Tinkering?" Economic Journal, V. 109 (February): pp. F5-F15
  • Ian Steedman (2001) Consumption Takes Time: Implications for Economic Theory, Routledge
  • S. Abu Turab Rizvi (2001) "Preference Formation and the Axioms of Choice", Review of Political Economy, V. 13, N. 12 (Nov.): pp. 141-159
  • John Von Neumann and Oskar Morgenstern (1953) Theory of Games and Economic Behavior, Third Edition, Princeton University Press

Wednesday, March 03, 2010

Labor Market Flexibility

Some mainstream economists claim that unemployment would be less if labor markets were more flexible and less rigid. In a 1998 paper arguing against this view, Bob Solow explains what this labor market rigidity that so many mainstream economists, especially "freshwater" economists, want to abolish is:
"My first observation is that 'labour-market rigidity' is never defined very precisely or directly in this context, but only be enumeration of tell-tale symptons. Thus a labour market is inflexible if the level of unemployment-insurance benefits is too high or their duration is too long, or if there are too many restrictions on the freedom of employers to fire and to hire, or if the permissible hours of work are too tightly regulated, or if excessively generous compensation for overtime work is mandated, or if trade unions have too much power to protect incumbent workers against competition and to control the flow of work at the site of production, or perhaps if statutory health and safety regulations are too stringent. It seems clear that those who point to labour-market rigidity as the source of high unemployment have something other than simple nominal or real wage rigidity in mind, or so shall I assume." -- Robert M. Solow, "What is Labour-Market Flexibility? What is it Good for?", Proceedings of the British Academy, V. 97
As I understand it, many of these "rigidities" were put in place in the United States context around the time of the New Deal with the cooperation and assistance of Institutionalist economists, a school with some sense of the real world.

Saturday, February 27, 2010

Bank for International Settlements (BIS) - Receptive to Heterodoxy?

I never even heard of the Bank for International Settlements (BIS) before a couple years ago. I am vaguely aware of the Basel accords, which I guess they have something to do with.

I have come across two papers - a ridiculously small number of data points - which make me wonder if they are receptive to heterodox economics. William White, the former chief economist of the BIS, criticized last December the direction of research in modern macroeconomics. He thinks macroeconomists should pay more attention to Hyman Minsky and also Austrian Business Cycle Theory. In a current BIS working paper (H/T to D-Squared), Piti Disyatat rejects the loanable funds theory and argues for the theory of an endogenous money supply, if I understand correctly. This paper references, among others, Basil Moore, Thomas Palley, and Randy Wray.

Tuesday, February 23, 2010

Colin Rogers and Ian Steedman Down Under

Colin Rogers has a review essay of Geoff Tily's Keynes's General Theory, the Rate of Interest and 'Keynesian' Economics: Keynes Betrayed:
"Tily (chapter 4) carefully documents how this Robertson version of 'Keynesian' economics succeeded in squeezing out Keynes' vision. The model behind Robertson’s vision is instantly recognisable by all students of economics today and consists of the idea that there exists a unique long-run equilibrium around which the economy fluctuates during booms and recessions... Apart from the fact that Keynes ... described rigidities as the classical explanation for unemployment, Tily makes it clear that this 'Keynesian' interpretation overlooks entirely that Keynes was concerned with the existence of multiple long-period equilibria in the General Theory. -- Colin Rogers, "Keynes vs the Keynesians: Keynes Rediscovered", History of Economics Review, Winter 2008.
I have never quite understood the idea that Keynesian policy is about helping the economy reach equilibrium quicker. I thought The Arrow-Debreu model of intertemporal equilibria was the canonical neoclassical explanation of prices. That model doesn't allow for out-of-equilibrium behavior in real time. By now, it should be trivial to create models of multiple long-run equilibria. Keynes' explanation for multiple long-run equilibria, I think, had to do with long-run expectations - each state of expectations creates a different (set of?) long run equilibrium.

Ian Steedman reviews another volume in Hayek's collected works:
"Laurence White has been zealous in providing editorial footnotes to Hayek’s text and many of his notes are indeed helpful... Some footnotes seem to be quite unnecessary explications... The simple observation by Hayek, that the choice of production method may change in response to a relative input price change, is made the occasion of a long and irrelevant note on the 'economics of socialism' debate..., while an editorial reference to the 'reswitching controversy' cites a single discussion thereof – one by Leland Yeager! ... It might be felt here that Hayek’s text is being used for the promotion of ‘Austrian’ economics more generally." -- Ian Steedman on "F. A. Hayek. The Pure Theory of Capital. Volume 12 of the Collected Works of F. A. Hayek, History of Economics Review, Summer 2009.

Saturday, February 20, 2010

Fred Lee's New History of Heterodox Economics

Frederick Lee has written a book: A History of Heterodox Economics: Challenging the Mainstream in the Twentieth Century. I don't know if I'm going to purchase this Routledge book. I've read papers many of the chapters grew from.

Saturday, February 13, 2010

Alex Haley and John Maynard Keynes: Self-Confident Authors

Alex Haley used to hang out at the Savoy, a local restraurant in Rome, NY. While writing Roots, he told the owner, "I am writing a book that is going to change how white people look at black people in America."

While writing The General Theory of Employment, Interest, and Money, Keynes had an argument with George Bernard Shaw about Marx. Keynes wrote to Shaw on 1 January 1935:
"...To understand my state of mind, however, you have to know that I believe myself to be writing a book on economic theory, which will largely revolutionise - not, I suppose, at once but in the course of the next ten years - the way the world thinks about economic problems. When my new theory has been duly assimilated and mixed with politics and feelings and passions, I can't predict what the upshot will be in its effects on actions and affairs. But there will be a great change, and, in particular, the Ricardian foundations of Marxism will be knocked away.

I can't expect you, or anyone else, to believe this at the present stage. But for myself I don't merely hope what I say, - in my own mind I'm quite sure."
I don't accept that Marx built on Say's Law, which is what Keynes refuted.

Tuesday, February 09, 2010

Notre Dame Faculty Senate Defends Academic Freedom

Maybe Phil Mirowski and his more interesting colleagues will be able to pursue their vocation.

Saturday, February 06, 2010

Garrison Orally On Reswitching

The following is from the Question and Answer session for Roger Garrison's recent lecture, "Macroeconomics: The Boom and Bust Cycle" (starting at about 59:29):
Audience member: "Can you reconcile using Hayekian triangles with reswitching and [unclear]?"

Garrison: "Yeah. The question is, 'How do you reconcile the Hayekian triangle with the Cambridge Capital Controversy, which involves capital-reswitching and technique reversing. I got that backwards - isn't it technique reswitching and capital reversing. Let me just take a poll here. How many have heard of the Cambridge Capital Controversy and know about technique reswitching and capital-reversing? Good, OK, good. One guy.

Let me just give you a standing-on-one-foot explanation. Capital theorists in Cambridge - this is Cambridge, England - argued that Böhm-Bawerk didn't have it quite right. His math was too simple, and if you allow for inputs and outputs to be expressed by polynomials, instead of rectangles or linear inputs, you find that the production process could lengthen or shorten with the change in the interest rate. If the interest rate falls, maybe it will shorten, or maybe it will lengthen. And you don't know. You have to look at the math and see how it turns out.

And the way the math turns out, there are only trivial exceptions - very small exceptions to the proposition that a low interest rate encourages long-term investment. You can come up with counterexamples, but even Cambridge capital-theorists, like Joan Robinson - she wrote an article, "The Unimportance of Reswitching" - just the magnitude doesn't amount to anything. If you read Hayek's Pure Theory of Capital, he acknowledges that, yes, yes, you can have funny profiles that seem to run counter to the general proposition that a low interest rate encourages long-term production. But those are very trivial. I've published articles on this. I can give you a link to one. But one thing I observed is that to get numbers where the reswitching is visible to the naked eye, you have to have the interest rate changing from 100% to 50%, or something like that, which itself suggests how minor that distinction is.

There are actually more fundamental criticisms that are based on how the Cambridge capital theorists measure roundaboutness. And the Austrians don't really measure it. They don't need to measure it. It's enough to show you the pictures. You saw the picture of the Research and Development chemist. You saw the picture of the retail clerk. That's what we are talking about, however you describe that mathematically. So I think, economically, that just doesn't work.

There are economists - Post Keynesians are the main ones - who throw up that Cambridge Capital Controversy as a killer of Austrian Business Cycle theory. They see that as the basis for just dismissing Austrian Business Cycle theory, but I think with very little justification."

References:
  • Roger M. Garrison (1979) "Comment: Waiting in Vienna", in Time, Uncertainty and Disequilibrium: Exploration of Austrian Themes (ed. by M. J. Rizzo), D. C. Heath and Company
  • Roger M. Garrison (2006) "Reflections on Reswitching and Roundaboutness", in Money and the Markets: Essays in Honor of Leland Yeager (ed. by R. Kopl), New York:Routledge.

Sunday, January 31, 2010

Austrian Business Cycle Theory As Uninteresting And Esoteric

I have been unsuccessful in getting my refutation of Austrian Business Cycle Theory accepted for publication in a peer-reviewed journal. My latest publically available version is downloadable from SSRN. I have had a later version rejected a couple of weeks ago. This version's references include Roger Garrison's 2006 "Reflections on Reswitching and Roundaboutness". I hope quoting an extract from a review is acceptable, since some might find this of interest:
"Hayek had washed his hands of the triangles [that ground his theory of the trade cycle] long before the ink was dry on his Pure Theory of Capital... Modern Austrian school economists like Roger Garrison still find the triangle-logic compelling, but I have the impression that, with the possible exception of Leland Yeager’s 1976 Economic Inquiry paper, no systematic attempt has been made to show that Austrian economics is immune to the capital critique; the arguments are intuitive rather than carefully drawn. (Even Yeager’s piece struck me when I read it, many years ago, as largely intuitive.) ...the arguments had never been put forward in a robust way..."

Tuesday, January 26, 2010

Classical Cross Dual Dynamics

"The actual price at which any commodity is commonly sold is called its market price. It may either be above, or below, or exactly the same with its natural price.

The market price of every particular commodity is regulated by the proportion between the quantity which is actually brought to market, and the demand of those who are willing to pay the natural price of the commodity, or the whole value of the rent, labour, and profit, which must be paid in order to bring it thither. Such people may be called the effectual demanders, and their demand the effectual demand; since it may be sufficient to effectuate the bringing of the commodity to market...

...The natural price, therefore, is, as it were, the central price, to which the prices of all commodities are continually gravitating...

The whole quantity of industry annually employed in order to bring any commodity to market, naturally suits itself in this manner to the effectual demand. It naturally aims at bringing always that precise quantity thither which may be sufficient to supply, and no more than supply this demand." - Adam Smith, The Wealth of Nations, Book I, Chapter VII


1.0 Introduction
Contemporary economists have elaborated Smith's metaphor of the gravitational attraction of market prices to natural prices. Elaborations consist of formal models of cross-dual dynamics.

Systems of equations describing prices and quantitites are dual systems in the post Sraffa/von Neumann tradition. Dynamics are cross dual when changes in prices respond to quantities and changes in quantities respond to prices. In particular, industries expand in which rates of profits are high and contract in industries in which profits are low. And prices fall in industries in which the quantity supplied exceeds the effectual demand. Prices rise in industries in which the quantity supplied is below the effectual demand.

Dupertuis and Sinha (2009) is one immediate impetus for my setting out this model of the reallocation of labor for a given wage. I don't think I thoroughly understand models of cross-dual dynamics. I think they are of interest for exploring the possible dynamics of market prices in competitive capitalist economies. I don't see that they are directly empirically applicable. For that, one needs to worry about markup prices and the degree of utilization of capacity in various industries.

2.0 Natural Prices
The data of our problem are:
  • The n x n input-output matrix A, where n is the number of industries and ai, j is the amount of the ith commodity used as input per unit output of the jth industry
  • The n-element row vector a0 of labor inputs, where a0, j is the amount of person-hours hired per unit output in the jth industry
  • The money wage wgiven
  • The composition of net output as expressed in the n-element column vector cgiven.
This is a circulating capital model in which all production processes use up their inputs in a year. Labor is assumed to be paid their wages at the end of the year. Only economies capable of producing a surplus product are considered. For simplicity, assume Constant Returns to Scale (CRS) and that every commodity is basic, in Sraffa's sense. This section considers the problem of finding:
  • The natural prices, as expressed in the n-element row vector p*
  • The corresponding wages w*
  • The corresponding rate of profits r*
  • The effectual demand as expressed in the n-element column vector of gross quantities q*
  • The n-element column vector of net quantities y*.

In the system of natural prices, the same rate of profits are made in every industry:
p* A(1 + r*) + a0 w* = p*
I take the net output as the numeraire.
p* y* = 1
In my formulation here, the wage is taken as a given ratio of the net output:
w* = wgiven
The above equations comprise the price system for natural prices.

Net outputs and gross outputs are related by the following equation:
y* = q* - A q* = (I - A) q*
where I is the identity matrix. I normalize the units of labor such that one unit is employed throughout the economy:
a0 q* = 1
Finally, the net output is assumed to be in the specified proportions. That is, there exists a positive constant k such that
y* = k cgiven

The above systems of equations are sufficient to determine gross and net effectual demands, natural prices, and the distribution of income. (An alternative specification would take the composition of gross output as given, instead of the net output. Perhaps outputs should be in units of Sraffa's standard commodity.)

3.0 Initial Condititions
The problem in the remaining sections is to define a dynamic process for the quantities produced q(t) and the market prices p(t) for t = 0, 1, 2, ... The initial quantities q(0) and market prices p(0) are givens. For the sake of the argument, I consider a dynamic process in which the amount of labor employed and the value of net output are invariant. So the initial quantities and prices must satisfy the following equations:
a0 q(0) = 1

p(0) y(0) = p(0)(I - A)q(0) = 1

4.0 Reallocation of Labor
Define raverage(t), the average rate of profits for the economy as a whole at time t:
raverage(t) = [p(t)(I - A - a0 wgiven)q(t)]/[p(t) A q(t)]
The numerator in the expression on the right hand side above is the value of the surplus product remaining in the capitalists' possession after replacing the means of production and paying laborers their wages. The denominator is the value of the capital goods advanced.

Typically, the rate of profits will vary from the average among the industries. The rate of profits for the jth industry at time t is:
rj(t) = [pj(t) - p(t) a., j - a0, j wgiven]/[p(t) a., j]
where a., j is the jth column of the input-output matrix A.

Define Raverage(t) to be the n-element column vector with each element equal to the average rate of profits. Let R(t) be the n-element column vector with each element being the rate of profits for the corresponding sector.

Now dynamics of the quantities of produced commodities can be specified:
q(t + 1) = [1/f1(t)]{[R(t) - Raverage(t)] + q(t)}
Or, in terms of scalars:
qi(t + 1) = [1/f1(t)]{[ri(t) - raverage(t)] + qi(t)}
where
f1(t) = 1 + a0[R(t) - Raverage(t)]
The denominator f1(t) above is a normalization that ensures the quantity of labor employed is always unity. The numerator ensures that the more the rate of profits in a sector exceeds the average, the faster that sector will expand in comparison with other sectors. (An alternative formulation might compare the rate of profits in each industry with the rate of profits r* in the system of natural prices.)

5.0 Price Changes
Price dynamics are here set out more directly:
p(t + 1) = [1/f2(t)]{p(t) - [qT(t) - q*T]}
where xT is the transpose of the vector x. In terms of scalars, prices are given by:
pi(t + 1) = [1/f2(t)]{pi(t)- [qi(t) - q*i]}
The time series f2(t) is defined as follows:
f2(t) = [q*T - qT(t)](I - A)q(t + 1)} + p(t)(I - A)q(t + 1)
The denominator f2(t) above is, again, a normalization condition. In this case, the normalization ensures the value of the net output is equal to unity. Since the composition of net output typically changes over the course of the process, the real wage varies in terms of any fixed commodity basket. It does remain, however, a given ratio of the net output.

6.0 Conclusion
I have set out above a model of a dynamic process, but without an analysis of its properties. An obvious theorem is that if initial quantities and prices happen to be equal to the effectual demands and natural prices, they will be left unchanged by the dynamics of market adjustments. In other words, the natural system is a stationary point of this dynamic process.

An interesting question is the trajectory of market prices, given an arbitrary starting point. I don't expect the process to necessarily converge to the natural system. At this point, I don't have any numeric examples of limit cycles or chaotic behavior. A failure of local stability doesn't bother me; I have often thought of Sraffa's work as pointing towards the possibility of complex dynamics arising in models of capitalist economies.

Questions of structural stability are of interest as well. Do dynamic properties of the system depend on the level of wages, especially if one introduces into the model a choice of technique? And how do the answers to these questions vary, if at all, with alternative modeling assumptions, some of which I have indicated? I do not know that the literature has reached definitive answers to these questions.

Update (28 January 2010): I have redefined the dynamics above in a way that seems more reasonable to me.

References
  • Michel-Stéphane Dupertuis and Ajit Sinha, "A Sraffian Critique of the Classical Notion of Centre of Gravitation", Cambridge Journal of Economics, V. 33 (2009): 1065-1087.

Sunday, January 24, 2010

Upcoming URPE Conferences

Chris Pepin informs us that the Union for Radical Political Economics (URPE) will participate in the upcoming Eastern Economics Association (EEA) conference. The conference will be held at the Loews Philadelphia Hotel, February 26 - 28. A program is available. This year is the 50th anniversary of the publication of Sraffa's book.

URPE is also participating in the Left Forum, on March 19-21 at Pace University.

Elsewhere

  • Eric Rauchway tells us about the Bretton Woods conference, where John Maynard Keynes showed that some economists could be more useful than dentists.
  • David Ruccio reprints a cartoon by B. Deutsch making fun of economists prefering a supposedly elegant theory of the minimum wage to empirical results falsifying the theory.
  • Bill Mitchell has a negative view of Greg Mankiw's textbook.

Wednesday, January 20, 2010

Skimming Moshe Adler

A few weeks ago, in a bookstore a couple of hundred miles away from here, I skimmed Moshe Adler's Economics for the Rest of Us: Debunking the Science that Makes Life Dismal. I did not purchase it because I am already too far behind in my reading. It is targeted for those outside the economics profession.

It is a short and approachable book that, as I recall, falls into two main parts.

The first part is about the mainstream economist's concept of (Pareto) efficiency. I hopped over this section fairly quickly, since I see no need to be strongly guided by this criterion in making policy decisions. I gather Adler agrees.

The second part is about income distribution, the theory of marginal productivity, and wages. Adler compares and contrasts neoclassical theory and the more empirically applicable classical theory. If I read this book in more depth, I would probably have some caveats about Adler's interpretation of the classical economists and his assignment to them of one (non-Malthusian) theory of wages. Adler recognizes that in a theory in which wages are determined by well-behaved supply and demand functions for labor, the imposition of higher wages results in less employment. Less security and less employment is a bad thing for many members of that vast majority in capitalist societies who depend on income from labor to live. On the other hand, when wages are the result of class struggle, as in Adam Smith, for example, the theory does not predict that unions, minimum wages, less "flexible" labor markets will result in less employment. And, despite the poppycock mainstream economists teach, that is the world we live in.

I agree with the author. Economics took a mostly wrong turning more than a century ago. I don't think that this book will convince many mainstream economists. If Adler wanted to convince mainstream economists, he would have had to written a more impenetrable book. I think Adler does address some of the questions raised by the current global economic crisis.

(I realize I am behind in responding to comments on previous posts.)

Saturday, January 16, 2010

The First Communist

One can find all sorts of things on the internet, such as T-shirts.


And one can find lots of silliness: "Why Jesus Christ is Not a Communist".

Hat tip: My friend Lucas.

Sunday, January 10, 2010

Leontief's Work As Applied Sraffianism

Sraffa's critique is formulated in terms of physical quantity flows among industries and labor inputs into each industry. From this data, institutional assumptions, and, for example, the rate of profits, Sraffa deduces the set of constant prices that allow for the smooth reproduction of a capitalist economy.

Leontief independently developed the theory of Input-Output (I-O) analysis, and national income accounts include I-O accounts. The Bureau of Economic Analysis maintains I-O accounts for the United States.

A body of work exists in which the national income accounts are used to examine empirical questions. Sometimes the output of each industry is normalized to one physical unit of each industry, thereby allowing the national accounts to be thought of as closer to Sraffa’s data. Much of this work can be seen as classical in approach, not marginalist. Benjamin H. Mitra-Kahn's "Debunking the Myths of Computable General Equilibrium Models" (2008) shows that the classical nature of one such body of empirical work is often disguised by tendentious and incorrect history.

So Sraffa’s work is empirically applicable, although his own intentions seem to have been more focused on criticism.

Saturday, January 02, 2010

Mainstream Economists Unable To Discuss Economics

Over on Economics Job Market Rumors, an anonymous poster asks:
"Despite the neoclassicals admitting that the Post-Keynesians were right, why has the impact of heterogeneous capital on an economy left out of the macro models?"
It will not surprise me if he or she receives no coherent answer. I recently had a chance to skim the transcripts of David Colander's interviews with graduate students at the "best" economics departments in the United States. These are in his book The Making of an Economist Redux. The following phrases seem no connote nothing to such students: "Cambridge Capital Controversy", "Neoclassical Economics", and "Post Keynesian Economics". One student responded to a question about Joan Robinson by asking, "Who's that?" The best students seem to realize that they will have to get an education by themselves in their "spare" time after they receive their doctorate.

Friday, January 01, 2010

Minimum Wages In The U.K.

The Australian Fair Pay Commission's Minimum Wage Research Forum met in Melbourne on 30 and 31 October 2008. Stephen Machin summarized recent experience in the United Kingdom (in the 2008 Minimum Wage Research Forum Proceedings, Volume 1).

Minimum wages were set by industry in the United Kingdom up until 1993. The wage councils were abolished in 1993, except for the Agriculture Wages Board which continues to this day. Outside of agriculture, the UK did not have a minimum wage between 1993 and 1999. From 1999 on, the National Minimum Wage was in effect in the UK, as recommended by the UK Low Pay Commission, established in 1997 by the newly elected Labour government. Notice that the trend in employment visually appears unaffected by the introduction of the national minimum wage and subsequent increases in it. The trend appears the same before as afterwards. This seems like disconfirmatory evidence to me of the simple neoclassical model of wages and employment as determined by supply and demand functions. Some of us know that model is without theoretical foundation anyways.

Hat tip to Bill Mitchell