| This dissertation consists of two self-contained essays in macro and monetary economics, organized in the form of two chapters.;In the first chapter, I develop a model with limited commitment and endogenous monitoring to study the optimal number and size of banks. Banking arises endogenously because of economies of scale. The planner designates a fraction of ex-ante homogenous agents to be bankers and concentrates monitoring efforts on them. Having fewer bankers reduces total monitoring costs, but this means more deposits per banker. Having more deposits, however, increases the bankers' incentives to divert deposits for their own profit. The result is that the planner needs to give bankers some reward to dissuade such opportunistic behavior. The optimal number of banks is negatively related to the fixed and marginal monitoring costs, impatience, and the temptation to default, but positively related to the return on real investments. To implement efficient allocations, there is a tension between equilibrium with free entry and having positive bank profit for incentive reasons. When the tax on banks is not too high, there exist non-degenerate stationary equilibriums. The equilibrium allocation is optimal only if the government limits entry of banks. One natural way is to charge a tax on bankers and give a transfer to non-bankers; another way is to simply impose a quota by limiting the number of bank charters.;In the second chapter, using an overlapping generations model, I propose a resolution of the high household saving puzzle in China by analyzing the impact of the one-child policy and the resulting flattening of age-earning profiles on household saving behavior. Following Ben-Porath's (1967) human capital accumulation technology, with the implementation of the one-child policy, the initial human capital of each young worker who enters into the job market increases, which results in a decrease of the worker's on-the-job-training, and thus a flattening of age-earning profiles. The flattened age-earning profiles encourage younger cohorts to save more for consumption smoothing, and, therefore, provides an explanation for the high saving rates among the young. Both the data and the model demonstrate that the mechanism is valid. |
