A topic of continuing interest to me is the role that serious engagement with economic theory played in the formation and development of John Rawls's thought (link). To what extent were important aspects of the theory of "Justice as Fairness" influenced by elements of economic theory?
I'm inclined to think that we can look at Rawls's major papers between 1955 and 1971 as a fairly reasonable sample of the intellectual influences that affected the development of his thought. His first major paper, "Two Concepts of Rules," appeared in 1955, and A Theory of Justice appeared in 1971. All of his major papers are included in Collected Papers, so this is a fairly convenient way of surveying his thought during this first portion of his career.
So what can we learn from these papers when it comes to the influence of the economists on Rawls?
Here is an inventory of Rawls's references to economists from 1955 to 1971, from the essays included in Collected Papers.
Two Concepts of Rules (1955)
- Lionel Robbins, The Theory of Economic Policy in English Political Economy (1952)
- John von Neumann and Oskar Morgenstern, The Theory of Games and Economic Behavior (1947); R. Duncan Luce and Howard Raiffa, Games and Decisions (1957) (56)
- IMD Little, A Critique of Welfare Economics (1957); KJ Arrow, Social Choice and Individual Values (1951); JR Hicks, Value and Capital (1946); Tibor Scitovsky, Welfare and Competition (1952) 
- Jerome Rothenberg, The Measurement of Social Welfare; JC Harsanyi, "Cardinal Utility" (1953) and "Cardinal Welfare" (1955) 
- WJ Baumol, Welfare Economics and the Theory of the State; RD Luce and Howard Raiffa, Games and Decisions 
- KJ Arrow, Social Choice and Individual Values (1951)
- RD Luce and Howard Raiffa, Games and Decisions (1957) 
- Wilfredo Pareto, Manuel d'economie politique (1909) [135, 160]
- Nicholas Kaldor, An Expenditure Tax (1955) 
- JC Harsanyi, "Cardinal Utility" (1953), "Cardinal Welfare" (1955) 
- FY Edgeworth, "The Pure Theory of Taxation" (1958) 
- John von Neumann and Oskar Morgenstern, The Theory of Games and Economic Behavior (1947); Luce and Raiffa, Games and Decisions (1957) 
- RB Braithwaite, Theory of Games as a Tool for the Moral Philosopher (1955)
- IMD Little, Critique; KJ Arrow, Social Choice; JR Hicks, Value; JC Harsanyi, "Cardinal Welfare", Tibor Scitovsky, Welfare and Competition (1963) 
Second, there is a decided focus on several areas: welfare economics, social choice theory, and game theory. Von Neumann and Morgenstern are cited several times, as are Luce and Raiffa; and Kenneth Arrow and John Harsanyi are repeat visitors as well. (Amartya Sen is cited in later essays, but not prior to 1971.) Keynes is not mentioned in these early articles, and only tangentially in TJ. And there is no mention of general equilibrium theory.
Third, none of these citations corresponds to a significant or substantive discussion of the economist's views. Rather, Rawls tends to illustrate a philosophical point by finding a relevant theoretical claim in one economist or another. This indicates a degree of familiarity with the contemporary literature, but a fairly low level of intellectual engagement with the debates and analytical approaches. In contrast to his treatment of utilitarianism, Kant, or Rousseau, Rawls's treatment of economic theory is brief and non-substantive.
Significantly absent from this inventory of references is any mention of the classical political economists. The index of Collected Papers contains no references to Ricardo, Quesnay, or Malthus, and only one reference to Adam Smith (ideal spectator theory; 201). John Stuart Mill is discussed in some detail, but always as a utilitarian philosopher, not an economist. Marx is mentioned briefly (Critique of the Gotha Programme; 252). The labor theory of value -- the central construct of classical political economy -- is not mentioned once.
There are a few references to Smith in A Theory of Justice, but they are superficial and incidental: Smith as a utilitarian, the concept of the invisible hand (57), the moral sentiments (184, 479), and impartial spectator theory (263). There is nothing to suggest a careful or extensive reading of Smith, Ricardo, or Malthus in A Theory of Justice.
It is hard to avoid the conclusion that the history of economic thought played a limited role in Rawls's thought. Rawls was reasonably well acquainted with contemporary economics as of the 1950s and plainly found some aspects relevant to his philosophical agenda (Arrow, Harsanyi, von Neumann). But I don't find much reason to believe that Rawls's important philosophical insights on justice were very much shaped by a reading of the history of economics. Contemporary economists appear to have had greater influence -- decision theory, game theory, and social choice theory in particular.
(See an earlier entry on "Rawls and decision theory" for more on this; link.)