We correlate competitive bidding and profits in symmetric independent private value first-price auctions with salivary testosterone, estradiol, progesterone, and cortisol in more than 200 subjects. Females bid significantly higher and earn significantly lower profits than males. Moreover,...

In an experiment using two-bidder first-price sealed bid auctions with symmetric independent private values, we collected information on the female participants' menstrual cycles. We find that women bid significantly higher than men in their menstrual and premenstrual phase but do not bid...

We characterize the class of symmetric two-player games in which tit-for-tat cannot be beaten even by very sophisticated opponents in a repeated game. It turns out to be the class of exact potential games. More generally, there is a class of simple imitation rules that includes tit-for-tat but...

Most listed firms are freestanding in the U.S, while listed firms in other countries often belong to business groups: lasting structures in which listed firms control other listed firms. Hand-collected historical data illuminate how the present ownership structure of the United States arose: (1)...