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.     

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.     

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.     

Consistent conjectures and voluntary contributions to public goods: why the conventional theory does not work

The conventional theory of voluntary contributions to public goods assumes that each person maximises his utility taking other people's behaviour as given (Nash conjectures). It is now coming to be recognised that this theory is inconsistent with observed behaviour. This paper argues that the problems of the theory are compounded — and not, as some economists have argued, resolved — by relaxing the assumption of Nash conjectures. If individuals' conjectures are consistent, each person will hold the (correct) belief that other people's contributions are inversely related to his own. Under most reasonable assumptions, equilibrium is a state in which no-one contributes anything.     

“农校对接”叫好不叫座的原因及对策研究

“农校对接”是把农业合作社的农产品直接送到高校食堂的新型供销模式.在进行的过程中出现“叫好不叫座”的尴尬现象,原因在于：高校和农业合作社认识不足,政策扶持不足,采购模式和供应模式的矛盾,运作的模式不够规范,高校的需求不稳定,与之对接的农户销量难以保证.“农校对接”的完善对策在于：以法律合约作为保障,建立农校信息交流平台,完善农产品的检测体系,积极发展中介信息服务企业,加强对农业合作社的专业培训和特殊时期多轮支撑.     

When does growth trickle down to the poor? The Indian case

A theoretical analysis and several econometric tests have beenundertaken to examine whether the trickle down effect took placein rural India over a long time period. We found little evidenceto suggest that the trickle down effect had occurred at all;our analysis suggests that the emergence of capital-labour substitutionwas primarily responsible for preventing growth from reducingpoverty. The decline in poverty and a higher growth rate thattook place during the late 1970s and 1980s were largely a resultof government anti-poverty measures teamed with the more equitabledistribution of credit and inputs to smaller and marginal farmers.