INDUSTRIES FOR FREE TRADE 357 These are difficult to measure(and were generally not measured while tariffs remained high),but their relative importance increased in the late 197os.By that time,nearly 30 percent of all categories(not values)of American manufactured imports were affected by them.*8 One empirical study concludes,however,that these new NTBs have had only limited protectionist effects;as the authors point out,"on average over a full range of manufactured products,the protection given by NTBs that may limit or reduce imports...is not nearly as large as the protection afforded by tariffs...or natural barriers to trade...."They project that,"if the United States continues on its present policy course,the U.S.economy will be considerably more open in 1985 than it was in 1976."3 Thus the erection of NTBs in the 197os and 198os may have produced a small net increase in protection.But this increase did not approach the levels of the 19zos even though two key preconditions-serious economic distress and declining hegemony-characterized both periods.Given the fertile ground of the late 197os,protectionism could have grown rampantly,as it did in the Igzos.For some reason,it did not. OTHER EXPLANATIONS The question,then,is why trade policy was different in the igzos and 197os even though key pressures influencing it were similar.This puzzle has been addressed by a number of studies.Three answers,all of which focus on aspects of the international or domestic system that are different from the one central to this study,require examination.They should be seen less as competing than as being pitched at different levels of analysis. I maintain that the argument developed in this study has been neglected and that it is more basic than these others. One type of explanation looks at the international distribution of power,usually in terms of economic capabilities.It involves modifications of the hegemonic stability thesis,which,as has been shown,cannot in its original form explain the differences in policy outcomes between the 192os and the 197os.s Three modified arguments have been presented. First,it has been asserted that American hegemony has not declined enough to set off the expected protectionist response.3 Even though other *Robert Reich,"Beyond Free Trade,"Foreign Affairs 61 (Spring 1983),773-804,at 786. Peter Morici and Laura Megna,U.S.Economic Policies Affecting Industrial Trade:A Ouan- titative Assessment (Washington,DC:National Planning Association,1983),11. Ibid.,103. s'Krasner (tn.5). 3Bruce Russett,"The Mysterious Case of Vanishing Hegemony;or,Is Mark Twain Really Dead?"International Organization 39(Spring 1985),207-32;Susan Strange,"Still An Extraor- dinary Power,"in Raymond Lombra and Willard Witte,Political Economy of International and Domestic Monetary Relations(Ames:lowa State University,1982).INDUSTRIES FOR FREE TRADE 357 These are difficult to measure (and were generally not measured while tariffs remained high), but their relative importance increased in the late 1970s. By that time, nearly 30 percent of all categories (not values) of American manufactured imports were affected by them.28 One empirical study concludes, however, that these new NTBs have had only limited protectionist effects; as the authors point out, "on average over a full range of manufactured products, the protection given by NTBs that may limit or reduce imports. . . is not nearly as large as the protection afforded by tariffs . . . or natural barriers to trade. . . .''Z9 They project that, "if the United States continues on its present policy course, the U.S. economy will be considerably more open in 1985 than it was in 1976.30 Thus the erection of NTBs in the 1970s and 1980s may have produced a small net increase in protection. But this increase did not approach the levels of the 1920s even though two key preconditions-serious economic distress and declining hegemony-characterized both periods. Given the fertile ground of the late I~~OS, protectionism could have grown rampantly, as it did in the 1920s. For some reason, it did not. The question, then, is why trade policy was different in the 1920s and 1970s even though key pressures influencing it were similar. This puzzle has been addressed by a number of studies. Three answers, all of which focus on aspects of the international or domestic system that are different from the one central to this study, require examination. They should be seen less as competing than as being pitched at different levels of analysis. I maintain that the argument developed in this study has been neglected and that it is more basic than these others. One type of explanation looks at the international distribution of power, usually in terms of economic capabilities. It involves modifications of the hegemonic stability thesis, which, as has been shown, cannot in its original form explain the differences in policy outcomes between the 1920s and the 1970s.~' Three modified arguments have been presented. First, it has been asserted that American hegemony has not declined enough to set off the expected protectionist resp0nse.3~ Even though other 28 Robert Reich, "Beyond Free Trade," Foreign Affairs 61 (Spring 1983), 773-804, at 786. 'v Peter Morici and Laura Megna, U.S. Economic Policies Affecting Indwtrial Trade: A Quan￾titative Assessment (Washington, DC: National Planning Association, 1g83), I I. I" Ibid., 103. 3' Krasner (fn. 5). Bruce Russett, "The Mysterious Case of Vanishing Hegemony; or, Is Mark Twain Really Dead.?"International Organization 39 (Spring 1985), 207-32; Susan Strange, "Still An Extraor￾dinary Power," in Raymond Lombra and Willard Witte, Political Economy of International and Domestic Monetary Relations (Ames: Iowa State University, 1982). 3