This thesis contains two theoretical essays built upon the canonical models of social learning, and one that applies social learning theory to durable goods markets. The first chapter, "Non-Monotone Observational Learning", revisits the canonical social-learning model that rationalizes herding in the long run, to investigate the possibility of non-imitative behavior in the short run generated by non-monotone learning: ceteris paribus, when some predecessor(s) switch to actions revealing greater confidence in one state of the world, agents become less confident in that state. I characterize conditions on the underlying information structures that lead to non-monotone learning. In particular, in a general setting with continuous private sig...