Homophily in Peer Groups

Appendix of “Homophily in Peer Groups” The Costly Information Case

A behavior genetic analysis of the tendency for youth to associate according to GPA

Behavior genetic research has revealed that many “environmental” variables are partially influenced by genetic factors. Known as gene–environment correlation (rGE), this line of scholarship provides insight on how and why individuals select into certain environments. Juxtaposing this body of evidence with research on peer group homophily—the tendency for peers to resemble one another on certain...

Estimating Peer Effects in Longitudinal Dyadic Data Using Instrumental Variables

The identification of causal peer effects (also known as social contagion or induction) from observational data in social networks is challenged by two distinct sources of bias: latent homophily and unobserved confounding. In this paper, we investigate how causal peer effects of traits and behaviors can be identified using genes (or other structurally isomorphic variables) as instrumental varia...

Gender bias in scholarly peer review

Peer review is the cornerstone of scholarly publishing and it is essential that peer reviewers are appointed on the basis of their expertise alone. However, it is difficult to check for any bias in the peer-review process because the identity of peer reviewers generally remains confidential. Here, using public information about the identities of 9000 editors and 43000 reviewers from the Frontie...

Do Your Online Friends Make You Pay? A Randomized Field Experiment in an Online Music Social Network

Demonstrating compelling causal evidence of the existence and strength of peer to peer influence has become the holy grail of the modern research in online social networks. In these networks, it has been consistently demonstrated that user characteristics and behavior tend to cluster both in space and in time. There are two well known rival mechanisms that compete to be the explanation for this...