This thesis examines a number of issues regarding the Mortensen-Pissarides search and matching model's empirical performance. Chapter 1 documents the volatility puzzle with the Canadian data. The combined data from both Canada and the United States present an additional difficulty. Even if the unobserved value of leisure is allowed to be as high as required to fit the business cycle in the United States or in Canada, the model cannot reconcile the similar labor cycles with the large policy differences in the UI benefits and income taxes in the two countries when the value of leisure is assumed to be the same in both countries.Chapter 2 takes into account the realistic institutional features of the UI system and investigates the impacts of the UI benefits on the labor market outcomes. If entitlement to UI benefits must be earned with employment, generous UI is an additional benefit to an employment relationship, so it promotes job creation. If individuals are risk neutral, UI is fairly priced, and the UI system prevents moral-hazard unemployed workers, the generosity of UI has no effect on unemployment.Chapter 3 shows that the Mortensen-Pissarides search and matching model can be successfully parameterized to generate observed large cyclical fluctuations in unemployment and modest responses of unemployment to changes in the UI benefits. The key features behind this success are the endogenous eligibility for UI benefits and the heterogeneity of workers. With the linear utilities commonly assumed in the Mortensen-Pissarides model, a fully rated UI system designed to prevent moral hazard has no effect on unemployment. However, the UI system in the United States is neither fully rated nor able to prevent workers with low productivity from quitting their jobs or rejecting employment offers to collect benefits. As a result, an increase in UI generosity has a positive, but realistically small, effect on unemployment. This chapter answers the Costain and Reiter (2008) criticism with the Mortensen-Pissarides model.