The replicator dynamics does not lead to correlated equilibria

It is shown that, under the replicator dynamics, all strategies played in correlated equilibrium may be eliminated, so that only strategies with zero marginal probability in all correlated equilibria survive. This occurs in particular in a family of 4×4 games built by adding a strategy to a Rock-Paper-Scissors game.     

Why evolution does not always lead to an optimal signaling system

This paper gives a complete characterization of neutrally stable strategies for sender–receiver games in the style of Lewis, or Nowak and Krakauer [Lewis, D., 1969. Convention: A Philosophical Study. Harvard Univ. Press, Cambridge, MA; Nowak, M., Krakauer, D., 1999. The evolution of language. Proc. Nat. Acad. Sci. USA 96, 8028–8033]. Due to the dynamic implications of neutral stability, the replicator dynamics of this model does not necessarily lead to the rise of an optimal signaling system, where every state of the world is bijectively linked to one signal and vice versa, but it can be trapped in suboptimum situations where two (or more) signals are used for the same event, or two (or more) events are associated with one and the same signal.     

One-sided patience with one-sided communication does not justify stackelberg equilibrium

The theory of games (with complete information) in which a single patient longrun player faces a succession of short-run opponents cannot plausibly be used to justify the Stackelberg solution concept, because if that player can select which subgame-perfect equilibrium is to be played then she can presumably also change her selection. Consequently, while she can choose among one-shot Nash outcomes, she cannot achieve the Stackelberg outcome.     

Hepatitis B does not explain male-biased sex ratios in China

Oster (2005) argued that parents with Hepatitis B (HBV) have more sons, which explained Asia's “missing women”. Lin and Luoh (2008) show no relationship between gender and mother's HBV. We test for a relationship between paternal HBV and son share and find none.     

Paying not to sell

In this paper we show that, in the presence of buyer and seller power, a monopolist can enter into a costly contractual relationship with a low-quality supplier with the sole intention of improving its bargaining position relative to a high-quality supplier, without ever selling the good produced by that firm.     

中小企业融资需方市场缘何失灵

中小企业融资难已成为制约其进一步发展的瓶颈。中小企业融资需方市场的有效运作,有赖于其自身素质的不断提高。因此,只有中小企业自身素质提高了,融资环境改善了,融资问题才能得以根本解决。     

Return of the lost letter: Experimental framing does not enhance altruism in an everyday context

Debate surrounds interpretation of prosocial behavior in experimental games. Skeptics of the thesis that evolution produced a propensity for noncontingent altruism speculate that such results reflect the presence of information suggesting reputational consequences, including awareness that one is participating in an experiment. To examine the effects on prosocial behavior of awareness that research is being conducted, return rates were measured on ‘lost’ envelopes, some of which carried the message that they were dropped as part of an investigation. Return rates were not enhanced by such messages, indicating that awareness that one is in an experiment does not increase prosocial behavior.