PROFIT, ENTRY AND CHANGES IN CONCENTRATION

The simultaneity between profit, entry, and changes in concentration is examined. The sample includes 481 observations on 4-digit industries over the years 1972-1977 and 1977-1982. Results show that profits respond positively to entry barriers and initial concentration. Net entry responds positively to initial profits and responds negatively to entry barriers. Concentration moves toward its steady-state level, but the rate of adjustment is very slow. The competitive process, left on its own, does not seem to move quickly toward equilibrium.