For the past two decades, economists have focused intensive effort on building Macroeconomics on a firm Microeconomic foundation. As Macroeconomic research are more integrated with Microeconomics, more and better micro evidence has been examined to verify Macroeconomic theories. One recent development in this line of research uses detailed firm-level evidence to modify current Macroeconomic theories. In this dissertation extensive firm-level evidence are studied to shed light on important macro issues such as investment dynamics, financial frictions, regulations and productivity growth. In this study firm behaviors are studied and modeled by utilizing theories from a variety of fields in Corporate Finance, Public Finance, International Econ...