Cooperation in anonymous dynamic social networks

Abstract We study the extent to which cooperative behavior can be sustained in large, anonymous, evolving social networks. Individuals strategically form relationships under a social matching protocol and engage in prisoner's dilemma interactions with their partners. We characterize a class of equilibria that support cooperation as a stationary outcome. When cooperation is possible, its level is uniquely determined. While neither community enforcement nor contagion mechanisms have force in our setting, the endogenous dynamics of the social network imply that cooperation allows an individual to gradually accumulate a large network of profitable interactions, while defection results in social marginalization. Even as players become perfectly patient, equilibrium allows for full cooperation, only autarky, or the coexistence of cooperation and defection, depending on payoffs. Smaller levels of cooperation can be sustained by a form of exclusivity among cooperators. * We than

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Price effects of the euro cash changeover: the role of product market competition

Euro cash changeover, Price effects, Product market competition, E31, D82, D43,