In connection with an earlier paper on the exchange of live donor kidneys (Roth, Sonmez, and Unver 2004) the authors entered into discussions with New England transplant surgeons and their colleagues in the transplant community, aimed at implementing a Kidney Exchange program. In the course of...

Most transplanted kidneys are from cadavers, but there are also substantial numbers of transplants from live donors. Recently, there have started to be kidney exchanges involving two donor-patient pairs such that each donor cannot give a kidney to the intended recipient because of immunological...

In the past, judges have often hired applicants for judicial clerkships as early as the beginning of the second year of law school for positions commencing approximately two years down the road. In the new hiring regime for federal judicial law clerks, by contrast, judges are exhorted to follow...

From 1986 through 1997 the entry-level market for American gastroenterologists was organized by a centralized clearinghouse. Before, and since, it has been conducted via a decentralized market in which appointment dates have unraveled to well over a year before the start of employment. The...

Many markets have organizations that influence or try to establish norms concerning when offers can be made, accepted and rejected. Examining a dozen previously studied markets suggests that markets in which transactions are made far in advance are markets in which it is acceptable for firms to...

This essay examines how repugnance sometimes constrains what transactions and markets we see. When my colleagues and I have helped design markets and allocation procedures, we have often found that distaste for certain kinds of transactions is a real constraint, every bit as real as the...

This essay discusses some things we have learned about markets, in the process of designing marketplaces to fix market failures. To work well, marketplaces have to provide thickness, i.e. they need to attract a large enough proportion of the potential participants in the market; they have to...

The collapse of the clearinghouse for the entry-level gastroenterology labor market offers a unique opportunity to study how stable clearinghouses succeed and fail. To explore the reasons for the failure of the clearinghouse (and why failures of this kind of clearinghouse have been so rare), we...

Patients needing kidney transplants may have willing donors who cannot donate to them because of blood or tissue incompatibility. Incompatible patient-donor pairs can exchange donor kidneys with other such pairs. The situation facing such pairs resembles models of the "double coincidence of...

The deferred acceptance algorithm proposed by Gale and Shapley (1962) has had a profound influence on market design, both directly, by being adapted into practical matching mechanisms, and, indirectly, by raising new theoretical questions. Deferred acceptance algorithms are at the basis of a...