The paper focuses on the relation of competition to changes in productivity. Specifically, it compares the experience of AT&T Long Lines, operating in an increasingly competitive market, with that of eight local telephone monopolies. Both the estimation of total factor productivity growth and...

The paper examines historical changes in the duration of the interval between the commercial introduction of a new product and the time when entry by later competitors begins. The paper begins by examining a priori reasons why the duration of this interval in the U.S. economy may either expand...