Bootstrap-Based Improvements for Inference with Clustered Errors

Microeconometrics researchers have increasingly realized the essential need to account for any within-group dependence in estimating standard errors of regression parameter estimates. The typical preferred solution is to calculate cluster-robust or sandwich standard errors that permit quite general heteroskedasticity and within-cluster error correlation, but presume that the number of clusters is large. In applications with few (5-30) clusters, standard asymptotic tests can over-reject considerably. We investigate more accurate inference using cluster bootstrap-t procedures that provide asymptotic refinement. These procedures are evaluated using Monte Carlos, including the much-cited differences-in-differences example of Bertrand, Mullainathan and Duflo (2004). In situations where standard methods lead to rejection rates in excess of ten percent (or more) for tests of nominal size 0.05, our methods can reduce this to five percent. In principle a pairs cluster bootstrap should work well, but in practice a Wild cluster bootstrap performs better.clustered errors; random effects; cluster robust; sandwich; bootstrap; bootstrap-t; clustered bootstrap; pairs bootstrap; wild bootstrap.

Who Drives Divergence? Identity Signaling, Outgroup Dissimilarity, and the Abandonment of Cultural Tastes

People often diverge from members of other social groups: They select cultural tastes (e.g., possessions, attitudes, or behaviors) that distinguish them from outsiders and abandon tastes when outsiders adopt them. But while divergence is pervasive, most research on the propagation of culture is based on conformity. Consequently, it is less useful in explaining why people might abandon tastes when others adopt them. The 7 studies described in this article showed that people diverge to avoid signaling undesired identities. A field study, for example, found that undergraduates stopped wearing a particular wristband when members of the “geeky” academically focused dormitory next door started wearing them. Consistent with an identity-signaling perspective, the studies further showed that people often diverge from dissimilar outgroups to avoid the costs of misidentification. Implications for social influence, identity signaling, and the popularity and diffusion of culture are discussed

Review of \u3cem\u3eDoing Time Together: Love and Family in the Shadow of the Prison. Megan Comfort.\u3c/em\u3e Reviewed by Jonah A. Siegel.

Book review of Megan Comfort, Doing Time Together: Love and Family in the Shadow of the Prison. Chicago: University of Chicago Press, 2009. $55.00 hardcover,$22.00 paperback