This paper documents that in the US, men are more likely than women to work in both high-wage firms and high-wage industries. I then ask why this sorting occurs. I consider two main explanations: men and women have different preferences, and men and women have different opportunities. Through the lens of a simple random search model, I find that the dominant explanation for sorting is differences in opportunities. One implication of this result is that women are at firms that offer better nonpay characteristics, and this plays an important role in explaining the gender earnings gap.

The Bartik instrument is formed by interacting local industry shares and national industry growth rates. We show that the typical use of a Bartik instrument assumes a pooled exposure research design, where the shares measure differential exposure to common shocks, and identification is based on exogeneity of the shares. Next, we show how the Bartik instrument weights each of the exposure designs. Finally, we discuss how to assess the plausibility of the research design. We illustrate our results through two applications: estimating the elasticity of labor supply, and estimating the elasticity of substitution between immigrants and natives.

We quantify the employer's role in unemployment insurance (UI) take-up. Employer effects on claiming and appeals are substantial, and those effects are negatively correlated, consistent with appeals deterring claims. Low-wage workers are less likely to claim and more likely to have their claims appealed than median-wage workers. Employer effects help explain these income gradients, so equalizing employer effects on claiming would increase the progressivity of UI. Finally, the main source of targeting error in UI is that eligible workers do not claim.