We analyze a model in which agents make investments and then match into pairs to create a surplus. The agents can make transfers to reallocate their pretransfer ownership claims on the surplus. Mailath, Postlewaite and Samuelson (2013) showed that when investments are unobservable, equilibrium investments are generally ineﬀicient. In this paper we work with a more structured model that is suﬀiciently tractable to analyze the nature of the investment ineﬀiciencies. We provide conditions under which investment is ineﬀiciently high or low and conditions under which changes in the pretransfer ownership claims on the surplus will be Pareto improving, as well as examine how the degree of heterogeneity on either side of the market aﬀects investment eﬀiciency.
“Buy local” arrangements encourage members of a community or group to patronize one another rather than the external economy. They range from formal mechanisms such as local currencies to informal “I’ll buy from you if you buy from me” arrangements, and are often championed on social or environmental grounds. We show that in a monopolistically competitive economy, buy local arrangements can have salutary eﬀects even for selﬁsh agents immune to social or environmental considerations. Buy local arrangements eﬀectively allow ﬁrms to exploit the equilibrium price-cost gap to proﬁtably expand their sales at the going price.
We suggest that one way in which economic analysis is useful is by oﬀering a critique of reasoning. According to this view, economic theory may be useful not only by providing predictions, but also by pointing out weaknesses of arguments. It is argued that, when a theory requires a non-trivial act of interpretation, its roles in producing predictions and oﬀering critiques vary in a substantial way. We oﬀer a formal model in which these diﬀerent roles can be captured.
A large literature uses matching models to analyze markets with two-sided heterogeneity, studying problems such as the matching of students to schools, residents to hospitals, husbands to wives, and workers to ﬁrms. The analysis typically assumes that the agents have complete information, and examines core outcomes. We formulate a notion of stable outcomes in matching problems with one-sided asymmetric information. The key conceptual problem is to formulate a notion of a blocking pair that takes account of the inferences that the uninformed agent might make from the hypothesis that the current allocation is stable. We show that the set of stable outcomes is nonempty in incomplete information environments, and is a superset of the set of complete-information stable outcomes. We provide suﬀicient conditions for incomplete-information stable matchings to be eﬀicient.
Savage (1954) provided a set of axioms on preferences over acts that were equivalent to the existence of an expected utility representation. We show that in addition to this representation, there is a continuum of other “expected utility” representations in which for any act, the probability distribution over states depends on the corresponding outcomes. We suggest that optimism and pessimism can be captured by the stake-dependent probabilities in these alternative representations; e.g., for a pessimist, the probability of every outcome except the worst is distorted down from the Savage probability. Extending the DM’s preferences to be deﬁned on both subjective acts and objective lotteries, we show how one may distinguish optimists from pessimists and separate attitude towards uncertainty from curvature of the utility function over monetary prizes.
Diﬀerent markets are cleared by diﬀerent types of prices — seller-speciﬁc prices that are uniform across buyers in some markets, and personalized prices tailored to the buyer in others. We examine a setting in which buyers and sellers make investments before matching in a competitive market. We introduce the notion of premuneration values — the values to the transacting agents prior to any transfers — created by a buyer-seller match. Personalized price equilibrium outcomes are independent of premuneration values and exhibit ineﬀiciencies only in the event of “coordination failures,” while uniform-price equilibria depend on premuneration values and in general feature ineﬀicient investments even without coordination failures. There is thus a trade-oﬀ between the costs of personalizing prices and the ineﬀicient investments under uniform prices. We characterize the premuneration values under which uniform-price equilibria similarly exhibit ineﬀiciencies only in the event of coordination failures.
Diﬀerent markets are cleared by diﬀerent types of prices — a universal price for all buyers and sellers in some markets, seller-speciﬁc prices that are uniform across buyers in others, and personalized prices tailored to both the buyer and the seller in yet others. We introduce the notion of premuneration values — the values in the absence of any muneration (payments) — created by the buyer-seller match. We characterize the premuneration values under which uniform-price and personalized-price equilibria agree. In this case, we have eﬀicient allocations, including pre-match investment decisions, without the costs of personalized pricing. We then examine the ineﬀiciencies that arise when the premuneration values preclude the agreement of uniform-price and personalized-price equilibria. We view premuneration values as an important consideration in market design.
People may be surprised by noticing certain regularities that hold in existing knowledge they have had for some time. That is, they may learn without getting new factual information. We argue that this can be partly explained by computational complexity. We show that, given a database, ﬁnding a small set of variables that obtain a certain value of R2 is computationally hard, in the sense that this term is used in computer science. We discuss some of the implications of this result and of fact-free learning in general.
Keywords: Computational complexity, Linear regression, Rule-based reasoning
Economic theory reduces the concept of rationality to internal consistency. The practice of economics, however, distinguishes between rational and irrational beliefs. There is therefore an interest in a theory of rational beliefs, and of the process by which beliefs are generated and justiﬁed. We argue that the Bayesian approach is unsatisfactory for this purpose, for several reasons. First, the Bayesian approach begins with a prior, and models only a very limited form of learning, namely, Bayesian updating. Thus, it is inherently incapable of describing the formation of prior beliefs. Second, there are many situations in which there is not suﬀicient information for an individual to generate a Bayesian prior. Third, this lack of information is even more acute when we address the beliefs that can be attributed to a society. We hold that one needs to explore other approaches to the representation of information and of beliefs, which may be helpful in describing the formation of Bayesian as well as non-Bayesian beliefs.