The authors examine learning in all experiments they could locate involving one hundred periods or more of games with a unique equilibrium in mixed strategies, and in a new experiment. They study both the ex post ('best fit') descriptive power of learning models, and their ex ante predictive...

Organs for transplantation are a scarce resource. Paying to increase the supply of organs is illegal in much of the world. We review efforts to increase transplantation by increasing the supply of available organs from living and deceased donors. Progress has been made in increasing the...

In an experiment comparing two-person bargaining and multiperson markets in Israel, Japan, the United States, and Yugoslavia, market outcomes converged to equilibrium everywhere, with no payoff-relevant differences between countries. Bargaining outcomes were everywhere different from equilibrium...

Patients needing kidney transplants may have donors who cannot donate to them because of blood or tissue incompatibility. Incompatible patient-donor pairs can exchange donor kidneys with other pairs only when there is a "double coincidence of wants." Developing infrastructure to perform...

We report on the design of the new clearinghouse adopted by the National Resident Matching Program, which annually fills approximately 20,000 jobs for new physicians. Because the market has complementarities between applicants and between positions, the theory of simple matching markets does not...