Profits in the Long Run asks two questions: Are there persistent differences in profitability across firms? If so, what accounts for them? This book answers these questions using data for the 1000 largest US manufacturing firms in 1950 and 1972. It finds that there are persistent differences in profitability and market power across large US companies. Companies with persistently high profits are found to have high market shares and sell differentiated products. Mergers do not result in synergistic increases in profitability, but they do have an averaging effect. Companies with above normal profits have their profits lowered by mergers. Companies with initially below normal profits have them raised. In addition, the influence of other variables on long-run profitability, including risk, sales, diversification, growth and managerial control, is explored. The implications of antitrust policy are likewise addressed.

"This book reaffirms much of the core of mainstream industrial organization and thus is an important work for readers of this Review....The book presents a wealth of econometric results, using a variety of econometric methods...Mueller is, in all this, uncompromisingly objective and technically proficient. The book bristles with interesting research methods, some of them quite imaginative and all of them as strong as the data and current knowledge permit....Professor Mueller has raised here a number of other exciting issues that can't be covered in this brief review but all of them add to the importance and originality of this study. This book belongs on the desk of every specialist in industrial organization and others who're involved in the making of antitrust policy." Antitrust Law and Economics Review