Canadian and U.S. unemployment rates moved together within a narrow margin from 1961 to the mid‐1970s. Since then, Canadian rates have exceeded U.S. rates by large margins—at times as much as 3 percentage points. Throughout this period, interest rates in the two countries have been nearly identical. Aggregate demand stimulation by government deficits has been greater in Canada than in the U.S., and the trade surplus in Canada has added to demand while the trade deficit in the U.S. has subtracted from demand. Therefore, it seems that conventional Keynesian arguments cannot explain the recent differences in unemployment rates.Differences in labor market developments, however, can do so. During a period when real wages rose 35 percent in Canada, they fell 5 percent in the U.S. Since the recession of 1981, U.S. wages have dropped while Canadian wages have remained constant. Differences in labor productivity do not account for these developments. A strong case exists for the argument that the different paths of unemployment rates are due to different paths of real wage developments.It is argued that the causes for these differences in labor market conditions are associated with substantial growth and decreases in unionization rates in Canada and the U.S., respectively. In addition, the unemployment insurance system in Canada is shown to be considerably more generous than that in the