Robert W. Crandall examines the effects of the AT&T breakup and weighs the costs and benefits to the residential and business consumer. On balance, he finds that the efficiency gains from opening up the telephone industry have more than offset the possible efficiency losses, which may be caused by the sacrifice of economies of scale and scope or the absence of fully compatible equipment and services. The replacement of regulation with competition has led to greater productivity in the telephone industry, a more efficient rate structure, and lower equipment prices. Crandall traces the telecommunications evolution from its early beginnings as pairs of copper wires up through the historic 1982 decision to divest. He investigates the impact of technological changes, competition, and the advent of divestiture on the quality of service, local and interexchange service rates, productive efficiency, and income distribution. He also focuses on problems that linger after the breakup in the increasingly competitive but highly regulated sector.