In a recent issue of this Journal Lucas and Rapping (1969b) present some original and interesting views on the nature of equilibrium in labor markets. Unfortunately, in the process they seriously misinterpret some of the post-Keynesian literature, leaving the impression that their departure from generally accepted positions is much less substantial than is in fact the case. The issues they raise concerning the voluntary or involuntary nature of measured unemployment have important implications for policy. Although Lucas and Rapping do not explore these implications, they lurk close enough to the surface to make clarification of the issues a matter of importance. Lucas and Rapping explicitly assume that the labor market is in continuous short-run equilibrium at the current wage rate, where equilibrium has the meaning that quantity supplied is exactly equal to quantity demanded. In other words, the short-run labor supply is always equal to employment. Measured unemployment, though it is a component of long-run labor supply, is not part of the short-run supply. This is equivalent to assuming that measured unemployment is voluntary, though the authors believe that the distinction between voluntary and involuntary unemployment is not a useful one. The view just described sounds more classical than Keynesian, but the authors surprisingly assert that "many [post-Keynesian] writers appear to treat labor markets as being in equilibrium throughout the cycle" and specifically attribute this view to Lange and to Modigliani (Lucas and Rapping 1969b, p. 724, n. 3). This startling assertion arises out of confusion over a difference in view in the post-Keynesian literature in which Lange (1944) and Modigliani (1944) take one position and Patinkin (1965) and