In a recent article two American authors, Benjamin and Kochin (1979a), argide that Keynes was wrong in attributing much of abnormally high unemployment of interwar years to a deficiency of aggregate demand. They claim to have discovered alternative clue to riddle of high unemployment in interwar and to be able to show that the persistently high rate of unemployment in interwar Britain was due in large part not to deficient aggregate demand but to high unemployment insurance benefits relative to wages (ibid., p. 474). of unemployed standing watch in Britain at publication of General Theory was largely a volunteer army (ibid.). In making their case, Benjamin and Kochin present three sets of evidence. The first is a regression of unemployment on a measure of benefits-to-wages ratio, so-called replacement ratio, and on a measure of deviations of output from trend over period 1920-38. The second set of evidence concerns implication of lower rate of unemployment among juveniles than among adults, and third set consists of inferences to be drawn from differences in rate of unemployment between single and married women, at different times. All bodies of evidence are used to support hypothesis of existence of an association between replacement ratio and level of unemployment; but only first, namely, time-series regression, is used to establish amount of unemployment to be explained in this way. That amount is seen to depend on specific values of coefficients on replacement term and on output term in regression. Table 1 reports data which are used by Benjamin and Kochin. The figures for output are for net national product (Q) as given by Feinstein (1972). For W, Benjamin and Kochin derive a figure for average weekly earnings from data for annual wage and salaries