Dale T. Mortensen and Christopher A. Pissarides are the recipients (with Peter Diamond) of the Nobel memorial Prize in Economics 2010. They have made path-breaking contributions to the analysis of markets with search and matching frictions, which account for much of the success of job search theory and the flows approach in becoming a leading tool for microeconomic and macroeconomic analysis of labor markets. Both scientists have gained groundbreaking insightsthrough individual as well as joint research. Consequently, this volume not only features several papers which helped shape the equilibrium search model, including some early contributions which have initiated the research on what is known today as the search and matching model of the labor market, but italso presents a joint paper by the IZA Prize Laureates, which is a complete statement of the equilibrium search and matching model with endogenous job creation and job destruction. As part of the IZA Prize Series, the book presents a selection of their most important work which has highly enriched research on unemployment as an equilibrium phenomenon, on labor market dynamics, and on cyclical adjustment.