Has the rate of profit been falling the US or other industrialized countries? What are the factors that are directly responsible for its increase over time and what factors account for its decline? The rate of profit is one of the most important economic variables. It directly affects the rate of growth of an economy, both as a source of funds for new investment and as an inducement for new investment. It also has a direct bearing on the distribution of income within an economy, particularly between wage earners and owners of capital. Its movement over time is thus a major source of concern for the business community, the working populaton and public policy. The present volume aims to fill an important gap in the literature on this important economic and policy issue. This collection undertakes a rigorous statistical analysis of both profitability trends in the US and other advanced economies and of the factors that affect movement over time.