Why do brokers charge per-share commissions to institutional traders? What determines the commission charge? We examine commissions and order flow for a sample of institutional orders and find that most per-share commissions are concentrated at only a few price points, primarily 5 and 6 cents...

In many tournaments investments are made over time and conducting a review only once at the end, or also at points midway through, is a strategic decision of the tournament designer. If the latter is chosen, then a rule according to which the results of the different reviews are aggregated into...

This document contains four separate analyses, each with a different author, of the "Gans" committee report on the Bible codes (DP 364 of the Center for the Study of Rationality, June 2004). The analyses appear in alphabetical order of the authors' names. Three of the authors were members of the...

The Gibbard-Satterthwaite Theorem asserts the impossibility of designing a non-dictatorial voting rule in which truth-telling always constitutes a Nash equilibrium. We show that in voting games of complete information where a mediator is on hand, this troubling impossibility result can be...

The parental investment conflict considers the question of how much each sex should invest in each brood, thereby characterizing different animal groups. Each such group usually adopts a certain parental care pattern: female-care only, male-care only, biparental care, or even no parental care at...

A Nobel Prize in Economics was given to the psychologist Daniel Kahneman for his joint research with the late psychologist Amos Tversky on decision making under uncertainty and on subjective judgments of uncertainty. The two proposed Prospect Theory as a descriptive alternative to Utility...

The vertical inflorescences of the Mediterranean annual Salvia viridis carry many small, colorful flowers, and are frequently terminated by a conspicuous tuft of colorful leaves ("flags") that attracts insect pollinators. Insects may use the flags as indicators of the food reward in the...

We consider a simple dynamic “collective reputation” model of a market for an experience good into which we introduce imperfect quality inspections. In each period two markets operate: a prime market for sellers with a good reputation, and a regular market for all other sellers. In every...

We present three axioms for a power index defined on the domain of simple (voting) games. Positivity requires that no voter has negative power, and at least one has positive power. Transfer requires that, when winning coalitions are enhanced in a game, the change in voting power depends only on...