Book excerpt: Simple models of urban search matching -- Extensions of urban search-matching models -- Non-monocentric cities and search-matching -- Simple models of urban efficiency wages -- Extensions of urban efficiency wage models -- Non-monocentric cities and efficiency wages -- The spatial mismatch hypothesis : a search-matching approach -- The spatial mismatch hypothesis : an efficiency-wage approach -- Peer effects, social networks, and labor market outcomes in cities -- General conclusion -- Appendix A: basic urban economics -- Appendix B: Poisson process and derivation of Bellman equations -- Appendix C: The Harris-Todaro model.