Human utility embodies a number of seemingly irrational aspects. The leading example in this paper is that utilities often depend on the presence of salient unchosen alternatives. Our focus is to understand <i>why</i> an evolutionary process might optimally lead to such seemingly dysfunctional features...

We examine a strategic-choice handicap model in which males send costly signals to advertise their quality to females. Females are concerned with the net viability of the male with whom they mate, where net viability is a function of the male's quality and signal. We identify circumstances in...

We study why 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 link these...

Consider two agents who learn the value of an unknown parameter by observing a sequence of private signals. Will the agents commonly learn the value of the parameter, i.e., will the true value of the parameter become approximate common-knowledge? If the signals are independent and identically...

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...

"Buy local" arrangements encourage members of a community or group to patronize one another instead of 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...