The Impact of the National Industrial Recovery Act on Cartel Formation and Maintenance Costs
利用1933年通过和1935年废除国家工业复兴法带来的反垄断制度变化，分析其对卡特尔形成与维持成本的影响，发现临界集中度水平在制度变化前后出现波动，支持了Bradburd和Over的理论框架。
Antitrust regime shifts represented by the 1933 adoption and 1935 annulment of the National Industrial Recovery Act are postulated to have effects analogous to temporary achievement of Bradburd and Over's 'integrative concentration level' (Bradburd and Over, 1982); a level at which cartel formation and maintenance costs are outweighed by collusive spoils. 'Regime switching' analysis of Census of Manufactures data reveals a 'critical concentration level' of 60 percent in 1933, which disappears in 1935, and reemerges at 38 percent in 1937. The empirical results support the Bradburd and Over framework and suggest that temporary shifts in antitrust regimes may have lasting impacts on the ability of an industry to exercise market power. Copyright 1994 by MIT Press.