In a model of evolution driven by conflict between societies more powerful states have an advantage. When the influence of outsiders is small we show that this results in a tendency to hegemony. In a simple example in which institutions differ in their "exclusiveness" we find that these...

Consumer auctions were very popular in the early days of internet commerce, but today online sellers mostly use posted prices. Data from eBay shows that compositional shifts in the items being sold, or the sellers offering these items, cannot account for this evolution. Instead, the returns to...

This study quantifies the efficiency of a real-world bargaining game with two-sided incomplete information. Myerson and Satterthwaite (1983) and Williams (1987) derived the theoretical efficient frontier for bilateral trade under two-sided uncertainty, but little is known about how well...

We examine six molecules facing initial loss of US exclusivity (LOE, from patent expiration or challenges) between June 2009 and May 2013 that were among the 50 most prescribed molecules in May 2013. We examine prices per day of therapy (from the perspective of average revenue received by retail...

Dynamic defaults for recurring purchases determine what happens to consumers enrolled in a product or service who take no action at a decision point. Consumers may face automatic renewal, automatic switching, or non-purchase defaults. Privately optimal dynamic defaults depend on the...

This study explores empirically the price dynamics within two distinct market institutions - a double oral auction, which resembles modern asset markets, and a bilateral exchange market, which represents markets that have existed for centuries. To provide a theoretical basis to our...

It has been previously shown that for sufficiently large pools of patient-donor pairs, (almost) efficient kidney exchange can be achieved by using at most 3-way cycles, i.e. by using cycles among no more than 3 patient-donor pairs. However, as kidney exchange has grown in practice, cycles among...

As multi-hospital kidney exchange clearinghouses have grown, the set of players has grown from patients and surgeons to include hospitals. Hospitals have the option of enrolling only their hard-to-match patient-donor pairs, while conducting easily arranged exchanges internally. This behavior has...

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...

In this paper we present a comprehensive comparison of IPO placement methods in over 50 countries. We find that out of the three primary methods, fixed price public offers, auctions, and book building, auctions are least popular with issuers. Since auctions allow for price discovery while...