Book excerpt: This book develops a dynamic programming framework for the analysis of firms' joint investment and market exit decisions and reviews methods for econometric estimation of such models. In an empirical application of this framework, a version of this model that allows for financial constraints is estimated by structural methods, using a plant-level dataset for a sample of U.S. firms. The empirical analysis shows that both the plant's productivity and firm-level financial constraints have important effects on plant-level investment and exit decisions. The main contribution of the book to the empirical investment literature is the application of a mixed discrete-continuous Markov process framework to investment and exit decisions, and the structural estimation using a full-information maximum-likelihood method, the nested fixed-point algorithm.