In recent years three different quantitative studies measuring the extent of regulation in OECD nations have appeared. One analysis is based on an extensive review and quantification of laws and regulations; the other two are based on opinion data of those familiar with these regulations....

Using weighted concentration ratios for the entire economy, I argue that industrial concentration decreased in the U.S. from 1960 to the early 1980s and then began to increase. This rise in the last two decades of the 20 th century offsets any counteracting affects stemming from the growth of...