Stagnant levels of output and incomplete recoveries in the interwar business cycle have received fresh attention in recent work. Building on the work of Borchardt (1991 [1979]), Fisher and Hornstein (2001) calibrate an augmented RBC model of Germany's interwar economy. They find that sluggish productivity combined with high wage costs explain the depth of Germany's interwar depression. In the very different context of a dynamic Phillips curve, Dimsdale, et al. (2004) arrive at the same conclusion. Cole and Ohanian (1999, 2002) find that output in Great Britain and the United States failed to recover to historical trends after the Great Depression. Beaudry and Portier (2002) find that the labour policies of the Popular Front government contributed to stagnant output levels in France during the 1930s. A common perspective shared by these papers is that productivity growth was already low during the 1920s and failed to recover to trend before World War II.