aggregate scrappage rate divided by the rate expected from aging alone (M*t). The coefficient of determination is 0.64, indicating almost two-thirds of the variation of the actual scrappage rate from its trend in explained by changes in turnover and prices. In chart 2, values of the trend (M*tKt) are plotted as a dotted line and values of expected scrappage (St) as a dashed line. The continuous line represents the Polk aggregate observed scrappage values. Correlation of the estimates of the dashed line with the Polk estimates yields a coefficient of determination of 0.90.

Ryuzo Sato, Ronald F. Hoffman, Production Functions with Variable Elasticity of Factor Substitution: Some Analysis and Testing, The Review of Economics and Statistics, Vol. 50, No. 4 (Nov., 1968), pp. 453-460

any point in this region will converge to a quasiequilibrium state with a zero rate of growth of capital [2, p. 66]. The present note indicates that the steady-state growth equilibrium with a positive rate of growth of capital in this case is, in fact, globally stable. The erroneous result in [2] comes from the assertion that K(0) -0 implies K(t) 0 O for all t (p. 65). Instead this assertion should be stated as