The thesis is composed of three research articles. Based on a common theoretical and modeling foundation, by means of computational simulation, these three essays study different subjects relating to firm dynamics under the impact of financial constraints and macroeconomic fluctuations. Respectively, the first article explores functioning of market selection mechanism, the second focuses on firms’ Research and Development (R&D) investment patterns, the third analyzes effects of economic stimulus policies on firm dynamics. The research results demonstrate that the combination of presence of financial constraints and macroeconomic fluctuations may have significant effects on firm dynamics in the context of competitive market. From different angles of analysis, the effects could reveal failure of market selection mechanism, market structure distortion which disfavors firms’ R&D investment, and unequal repercussions of an economic stimulus on firms in recession, especially to the disadvantage of young and small ones.
