A probabilistic ghost in the experimental machine

This paper focuses on the opposition between two contemporary research programs in economics: behavioral economics (BE) and experimental market economics (EME). Our claim is that the arguments of this opposition can be clarified through the lens of another opposition in the philosophy of probability and in probability theory, between Bayesianism and frequentism. We show how this probabilistic opposition has indirectly shaped a controversy in psychology that opposes two research programs – Heuristics and Biases and Ecological Rationality – which play respective roles in the foundations of individual rationality in BE and EME. To understand these theoretical interrelationships, we investigate the 1996 controversy between Kahneman, Tversky, and Gigerenzer. Those psychologists held different views on how probabilistic representations influence the context-dependency of rationality. This provides a rationale to suggest that a probabilistic ghost may be haunting the experimental machine in economics, and explains how and why the oppositions between BE and EME are structured around the interplay between the norms of rationality and the context in which rationality is exercised.     

Corporate insurance with optimal financial contracting

Summary. This paper attemps to rationalize the use of insurance covenants in financial contracts, and shows how external financing generates a demand for insurance by risk-neutral entrepreneurs. In our model, the entrepreneur needs external financing for a risky project that can be affected by an accident during its realization. Accident losses and final returns are private information to the firm, but they can be evaluated by two costly auditing technologies. We derive the optimal financial contract: it is a bundle of a standard debt contract and an insurance contract with franchise, trading off bankruptcy costs vs auditing costs. We then analyze how this optimal contract can be achieved by decentralized trading on competitive markets when insurance and credit activities are exogenously separated. With additive risks, the insurance contract involves full coverage above a straight deductible. We interpret this result by showing how our results imply induced risk aversion for risk-neutral firms. Received: December 14, 1998; revised version: August 11, 1999     

Fully sincere voting

In a general social choice framework where the requirement of strategy-proofness may not be sensible, we call a social choice rule fully sincere if it never gives any individual an incentive to vote for a less-preferred alternative over a more-preferred one and provides an incentive to vote for an alternative if and only if it is preferred to the default option that would result from abstaining. If the social choice rule can depend only on the number of votes that each alternative receives, those rules satisfying full sincerity are convex combinations of the rule that chooses each alternative with probability equal to the proportion of the vote it receives and an arbitrary rule that ignores voters' preferences. We note a sense in which the natural probabilistic analog of approval voting is the fully sincere rule that allows voters maximal flexibility in expressing their preferences and gives these preferences maximal weight.     

Appraising Unhappiness in the Wake of the Great East Japan Earthquake

Considering the case of the Great East Japan Earthquake, we use the experienced‐utility approach to appraise the psychological distress from disaster‐related news. We take advantage of the serendipitous timing of our original nationwide weekly panel survey that became a fitting resource for the investigation of subjective well‐being in the immediate aftermath of the earthquake. Although all of Japanese society was affected, we found geographical heterogeneity between the affected areas (Sendai and Tokyo) and the unaffected areas in terms of mental costs. Our finding reminds us of the focusing effect (Kahneman et al., 2006 ; Dolan and Kahneman, 2008 ) as captured by Schkade and Kahneman ( 1998 ) in the maxim “Nothing in life is quite as important as you think it is while you are thinking about it”.     

Optimal Income Taxation with Risky Earnings: A Synthesis

We study optimal nonlinear income taxation when earnings can differ because of both ability and luck, so the income tax has both a redistributive role and an insurance role. A substantial literature on optimal redistribution in the absence of risk has evolved since Mirrlees's original contribution. The literature on the income tax as a social insurance device is more limited. It has largely assumed that households are ex ante identical so unequal earnings are due to risk alone. We provide a general treatment of the optimal income tax under risk when households differ in ability. We characterize optimal marginal tax rates and interpret them in terms of redistribution, insurance, and incentive effects. The case of ex ante identical households and the no‐risk case with heterogeneous abilities come out as special cases.     

Cheating in markets: A laboratory experiment

We develop a two-market model under three conditions: autarky, frictionless free trade, and free trade with cheating. With cheating, buyers can underpay by π% in cross-market trades and sellers can deliver π% of full value. We solve for competitive equilibrium with cheating and obtain novel testable predictions on price, volume and surplus. We test these in a laboratory experiment using parameters intended to challenge the theory. The results are generally consistent with competitive equilibrium. We find evidence of price unification, market segmentation, a cross-market volume of trade lower under cheating than in frictionless free trade, but a higher overall volume.     

A Graphical Approach to the Standard Principal-Agent Model

An obstacle to the teaching of principal-agent theory is the technical complexity and intractability of the general model. Even in academic studies strong assumptions are often imposed so as to derive an analytical solution. The author describes a graphical approach to the standard principal-agent model. Characterizing equilibrium in the contract space defined by the incentive parameter and insurance component of pay under a linear contract, this approach provides a simple and intuitive method for analyzing the principal-agent problem, which can be easily understood by students of economics with basic knowledge of algebra and differentiation. The approach has shown to be convenient and rich for comparative statics analyses.     

Moral Hazard,Income Taxation and Prospect Theory*

The standard theory of optimal income taxation under uncertainty has been developed under the assumption that individuals maximise expected utility. However, prospect theory has now been established as an alternative model of individual behaviour, with empirical support. This paper explores the theory of optimal income taxation under uncertainty when individuals behave according to the tenets of prospect theory. It is seen that many of the standard results are modified in interesting ways. The first‐order approach for solving the optimisation problem is not valid over the domain of losses, and the marginal tax schedule offers full insurance around the reference consumption level. The implications of non‐welfarist objectives under income uncertainty are also examined.     

Compensating for the winner's curse: Experimental evidence

We conduct experiments on common value auctions with rationing. In each auction, the good is randomly allocated to one of the k highest bidders, at the (k+1)st highest price. When k>1, bidders are rationed. As the degree of rationing increases, the equilibrium bid function increases. Consistent with prior literature, we find that bidders suffer from the winner's curse and lose money on average. However, bids in the experiments do adjust in the appropriate direction as the degree of rationing changes, providing support for the comparative statics implications of the theory. Our results are consistent with subjects having an intuitive understanding of the winner's curse, but being unable to compute the equilibrium bid levels.     

Prospect theory and liquidation decisions

We solve a liquidation problem for an agent with preferences consistent with the prospect theory of Kahneman and Tversky [Econometrica 47 (1979) 263-291]. We find that the agent is willing to hold a risky project with a relatively inferior Sharpe ratio if the project is currently making losses, and intends to liquidate it when it breaks even. On the other hand, the agent may liquidate a project with a relatively superior Sharpe ratio if its current profits rise or drop to the break-even point. Our results capture the spirit of the disposition effect and the break-even effect documented in empirical and experimental studies.     

A general model of insurance under adverse selection

Summary. This paper considers optimal insurance schemes in a principal-agent multi-dimensional environment in which two types of risk averse agents differ in both risk and attitude to risk. Risk corresponds to any pair of distribution functions (not necessarily ordered by any of the usual dominance relations) and attitudes to risk are represented by any pair of non-decreasing and concave utility functions (not necessarily ordered by risk aversion). Results obtained in one-dimensional models that considered these effects separately and under more restricted conditions, are preserved in the more general set-up, but some of the questions we study can only be posed in the more general framework. The main results obtained for optimal insurance schemes are: (i) Insurance schemes preserve the order of certainty equivalents; consequently, the latter constitute a one-dimensional representation of types. (ii) Agents with the lower certainty equivalent are assigned full insurance. Partial insurance assigned to the others may entail randomization. (iii) Partially insured positions are an increasing function of the ratios of the probabilities that the two types assign to the uninsured positions. Most of these properties are preserved when, due to competition or other reasons, the insured certainty equivalents can not be set below pre-determined levels. Received: January 13, 1998; revised version: October 10, 1998     

Health insurance and lifestyles

This article contributes to the discussion surrounding the existence of ex ante moral hazard and propitious selection in a voluntary private health insurance scenario. Moreover, it provides an estimation of the determinants of lifestyle choices and of private health insurance demand. A multivariate probit is estimated for health insurance demand and lifestyle decisions to take into account the potential endogeneity of these decisions. The results indicate that there is evidence of ex ante moral hazard in deciding to do sports and eating healthy snacks. Hence, no propitious selection has been found for these decisions. Another relevant result shows that there is no individual heterogeneity for the lifestyle choices, except for smoking, and private health insurance choice. Evidence from the results also supports the idea that there are nonobservable variables playing a role in the lifestyle decisions. These results provide some directions for policymakers, such as the promotion of precautionary behaviours and the use of implicit lifestyle drivers to promote healthy choices by people.     

Order Independence for Iterated Weak Dominance

In general, the result of the elimination of weakly dominated strategies depends on order. We definenice weak dominance. Under nice weak dominance, order does not matter. We identify an important class of games under which nice weak dominance and weak dominance are equivalent, and so the order under weak dominance does not matter. For all games, the result of iterative nice weak dominance is an upper bound on the result from any order of weak dominance. The results strengthen the intuitive relationship between backward induction and weak dominance and shed light on some computational problems relating to weak dominance.Journal of Economic LiteratureClassification Number: C72.     

Pareto efficient insurance contracts when the insurer's cost function is discontinuous

Summary. We consider the problem of efficient insurance contracts when the cost structure includes a fixed cost per claim. We prove existence of efficient insurance contracts and that the indemnity function in such contracts is non-decreasing in the damage. We further show that either there is no insurance, or the indemnity is positive for all losses, or efficient insurance contracts have a unique jump. We study variants of the model and provide a generalization to the case of non expected utilities. Our results are then applied to Townsend's model of deterministic auditing. Received: November 8, 2000; revised version: March 12, 2002 RID="*" ID="*" We are grateful to F. Salanié for pointing out an error in the previous version of the paper and for suggesting Proposition 6 to us. Correspondence to: R.-A. Dana     

WILL TAX‐BASED HEALTH INSURANCE REFORMS HELP THE SELF‐EMPLOYED STAY IN BUSINESS?

The self‐employed face a tax‐induced disadvantage relative to wage and salary workers when it comes to the payment of health insurance premiums. This paper uses a panel of individual tax return data to test whether lower health insurance premium costs because of an expanded tax incentive result in longer periods of self‐employment. The results suggest that households claiming the deduction are indeed less likely to exit self‐employment. Equalizing the treatment of health insurance premiums for the self‐employed and wage workers by allowing full deductibility from Self‐Employment Contributions Act (SECA) taxes would result in a 7% decrease in the probability of exit. (JEL H32, I18, L26)     

A solution to the random assignment problem on the full preference domain

We consider the problem of allocating a set of indivisible objects to agents in a fair and efficient manner. In a recent paper, Bogomolnaia and Moulin consider the case in which all agents have strict preferences, and propose the probabilistic serial (PS) mechanism; they define a new notion of efficiency, called ordinal efficiency, and prove that the probabilistic serial mechanism finds an envy-free ordinally efficient assignment. However, the restrictive assumption of strict preferences is critical to their algorithm. Our main contribution is an analogous algorithm for the full preference domain in which agents are allowed to be indifferent between objects. Our algorithm is based on a reinterpretation of the PS mechanism as an iterative algorithm to compute a “flow” in an associated network. In addition we show that on the full preference domain it is impossible for even a weak strategyproof mechanism to find a random assignment that is both ordinally efficient and envy-free.     

Learning in asymmetric duopoly markets: competition in information and market correlation

This paper explores experimentation and learning in asymmetric duopoly markets with product differentiation and demand uncertainty. We define the concepts of strategic substitutability and strategic complementarity in information and we show how both the mode of information competition and the transmission of information across markets affect duopoly experimentation. We relate information competition with market competition and we find that, when goods are substitutes and the correlation between market shocks is negative, firms will have a higher incentive to experiment in asymmetric markets than in symmetric ones. The opposite result follows when such correlation is positive. Also, when goods are complements the above findings are reversed.JEL Classification: D83, C72The authors thank partial financial support from the Spanish Ministry of Science and Technology under project B2000-1429, from the Spanish Ministry of Education and Science under project SEJ2004-07554 and from the “Generalitat Valénciana” under project GRUPOS04/13.     

Medical insurance with rank-dependent utility

Summary. A well-known result in the medical insurance literature is that zero co-insurance is never second-best for insurance contracts subject to moral hazard. We replace the usual expected utility assumption with a version of the rank-dependent utility (RDU) model that has greater experimental support. When consumers exhibit such preferences, we show that zero co-insurance may in fact be optimal, especially for low-risk consumers. Indeed, it is even possible that the first-best and second-best contracts are identical. In this case, there is no “market failure”, despite the informational asymmetry. We argue that these RDU results are in better accord with the empirical evidence from US health insurance markets. Received: February 26, 2001; revised version: October 4, 2002 RID="*" ID="*"The authors would particularly like to thank Simon Grant, John Quiggin, Peter Wakker and an anonymous referee for valuable comments and suggestions on earlier drafts. The paper has also benefitted from the input of seminar audiences at The Australian National University, University of Auckland, University of Melbourne and University of Sydney. Ryan also gratefully acknowledges the financial support of the ARC, through Grant number A000000055. Correspondence to:R. Vaithianathan     

Subjective evaluations of n-person games

Using an axiomatization of subjective expected utility due to Fishburn, we characterize a class of utility functions over a set of n-person games in characteristic-function form. A probabilistic value is defined as the expectation of some player's marginal contribution with respect to some probability measure on the set of coalitions of other players. We decribe conditions under which a utility function on the set of n-person games is a probabilistic value; we prove as well an analogous result for simple games. We present additional axioms that characterize the semivalues and, in turn, the Shapley and Banzhaf values.     

Marx,Sraffa, and Surplus: Observations Prompted by Garegnani (2018)

ABSTRACT

In a posthumously published article, Pierangelo Garegnani (2018. ‘On the Labour Theory of Value in Marx and in the Marxist Tradition.’) depicts Marx’s project in Capital as that of ‘developing systematically the theory of Ricardo and [the] implications of social conflict’ implied by Ricardo’s ‘surplus approach to value and distribution’. This paper argues to the contrary that Marx’s theory of surplus value and exploitation differs from (neo-)Ricardian surplus theory in fundamental ways, and modifies Garegnani’s simple Sraffian model to illustrate the distinctive implications of Marx’s theory.