In the first chapter, I evaluate the wage impacts from exogenous and endogenous peer effects within different metropolitan areas. I construct comparison groups for workers within the same industry and Public Use Microdata Area (PUMA) residence based on support from existing literature on social networks, and estimate peer and network effects in a spatial auto-regressive model with a network structure that in- corporates group fixed effects. Inclusion of these effects reveals that both observed and unobserved factors within each network have significant effects on individual outcomes. This is the first attempt to estimate the social effects on wages using the spatial econometric approach proposed by Lee (Journal of Econometrics 2007; 140(2),...