Despite their documented importance in the labor market, little is known about how workers use social networks to find jobs and their resulting effect on earnings. I use geographically detailed US employer-employee data to infer the role of social networks in connecting workers to jobs in high-paying firms. To identify social interactions in job search, I exploit variation in social network quality within small neighborhoods. Workers are more likely to change jobs, and more likely to move to a higher-paying firm, when their neighbors are employed in high-paying firms. Furthermore, local referral networks help match high-ability workers to high-paying firms.

Recent empirical findings have cast doubt on the neoclassical model of labor supply. However, estimation issues, and not workers’ behavior, may be responsible for these findings. This paper investigates this possibility by examining the daily labor supply of Florida lobster fishermen. I invariably find that fishermen work more when earnings are temporarily high, behavior that is consistent with a neoclassical model of labor supply. Furthermore, methods that do not control for measurement error and endogeneity of the wage not only produce downward-biased estimates of labor supply elasticities but also generate a spurious negative and significant elasticity of daily hours.

Immigration may affect the likelihood that US natives major in science or engineering. Foreign-born students may crowd US natives out of science or engineering, or they may have positive spillovers on US natives that attract or retain them in those fields. This study uses data on college majors from the 2009–11 American Community Surveys to examine the effect of the immigrant share in US natives’ age cohort while they are in high school or in college. We find some evidence that immigration adversely affects whether US-born women who graduated from college majored in a science or engineering field.

We present and calibrate a dynamic model that characterizes the labor market for computer scientists. In our model, firms can recruit computer scientists from recently graduated college students, from STEM workers working in other occupations or from a pool of foreign talent. Counterfactual simulations suggest that wages for computer scientists would have been 2.8-3.8% higher, and the number of Americans employed as computers scientists would have been 7.0-13.6% higher in 2004 if firms could not hire more foreigners than they could in 1994. In contrast, total CS employment would have been 3.8-9.0% lower, and consequently output smaller.