The consequences of the US DOJ's antitrust activities: A macroeconomic perspective

Do the antitrust law enforcement activities of the US Department of Justice act as exogenous "technology shocks" or as "markup shocks" limiting market power and promoting economic growth? We analyze annual time series data from 1947 to 2003 on three measures of federal antitrust intervention: the ratio of the Antitrust Division's budgetary expenditures to GDP as well as the numbers of civil and criminal antitrust cases instituted. We find that changes in the levels of these policy variables act like negative technology shocks and that the negative effects are transitory; antitrust policy generates no subsequent offsetting increases in productivity.