Three Essays in Macroeconomics

The scope of the dissertation is (broadly-defined) general macroeconomics. The first essay is on optimal taxation and capital structure, the second essay is on firm dynamics, and the third essay is on financial crises. The first essay clarifies the role of the corporate income tax (as a form of double taxation) for achieving socially optimal allocations in the Mirrlees framework when the government cannot tax unrealized capital income at the individual level. Use of the corporate tax requires changes in the individual capital tax. The novelty of the paper is that the sophisticated tax system is designed to influence the in-dividual agent’s portfolio choice of debt and equity, which in turn endogenizes the leverage ratio. The optimum corporate tax is indeterminate, but a minimal level is necessary. An immediate question is what happens to capital structure if we increase or decrease the level of the corporate tax. Surprisingly, unlike in classical capital structure theories, in this optimal tax mechanism, the firm’s leverage ratio is independent of the corporate tax rate