Catch-up in total factor productivity (TFP) among the group of seven was evident between 1870 adn 1979, though much slower before 1938 than after 1950. Capital:labor ratios also converged over the long period, though the process was much stronger after 1960. TFP catch-up is found to be positively associated with capital:labor growth and strongest when capital intensity is growing most rapidly. The United States overtook the United Kingdom in technological leadership in 1900 when its capital:labor growth was more than three times higher. The steady deterioration in the United Kingdom's relative TFP since 1900 and the United States' since 1950 are both associated with low rates of capital formation.

Marx's of the tendency of the rate of profit to has been the subject of much debate, both theoretical and empirical. The states that over time the organic composition of capital will tend to rise, thereby causing the general rate of profit to fall (vol. 3, ch. 13). At issue on the theoretical side are the analytical relations between the organic composition of capital and the general rate of profit and, more broadly, between labor values and prices of production. At issue on the empirical side are the actual movements of the organic composition and the general rate of profit over time. This paper will investigate both sides of this issue. The first part will develop and criticize the of the falling rate of profit. The presentation will rely heavily on the analytical apparatus developed for Marxian analysis over the last twenty years (see particularly Francis Seton, Michio Morishima and Seton, Paul Samuelson, Morishima, William Baumol, and John Roemer), as well as Jens Christiansen's review of the arguments. The major conclusion that will be drawn is that the general rate of profit does not necessarily move inversely to the organic composition of capital and there is thus no necessity for the rate of profit to fall with capitalist development. What remains of the law of the falling rate of profit is then the empirical question of whether in fact the rate of profit had fallen and, if so, what factors have contributed to its decline.' The second part of the paper will present empirical estimates of the general rate of profit, the organic composition of capital, and other key variables in the Marxian system for the 1947-67 period in the United States. The study is confined to this period because the required data (inputoutput tables) are available only for years 1947, 1958, 1963, and 1967. Two questions will be addressed. First, has the rate of profit fallen? Second, what is the observed relation of the rate of profit to the organic composition and other variables in the system? In this regard, particular attention will be paid to relative productivity increases over the period and their impact on the rate of profit, the organic composition, the rate of surplus value and other variables.

Puerto Rico's transformation from a preindustrial to an industralized economy in the period 1948-63 provides an opportunity to measure the impact of technological change on several basic parameters in a Marxian economic framework. The rate of surplus value (estimated using the Morishima-Seton transformation) remains relatively stable at 0.97 in 1948 and 0.93 in 1963, while the organic composition falls from 2.75 to 2.09. The stability in the rate of surplus value results from a 63 percent average fall in labor values counterbalanced by a 143 percent rise in labor's consumption. The rate of surplus value, when adjusted for trade flows, jumps to 1.31 in 1948 and 1.18 in 1963, due to Puerto Rico's large balance-of-trade deficit and the relative import intensity of labor's consumption.

Data are used for thirteen industrialized countries to investigate convergence of labor productivity levels in individual manufacturing industries over the 1963-82 period. The authors find convergence in virtually every manufacturing industry. Among these countries, the co efficient of variation of industry labor productivity declined in all but one of twenty-eight industries. However, productivity convergenc e is stronger for all manufacturing than within individual industries, especially heavy and high-technology industries. Also, variation in employment mix among countries plays little role in explaining cross-country differences i n aggregate manufacturing productivity, nor have changes in employment mixes been an important source of convergence.

In the literature, comparisons between absolute levels of productivity in different industries occur frequently. This paper explores the meaning and possible significance of such measures. Prices must be used to permit the required comparison of the outputs of different industries. It is shown that base-year weights produce a valid measure of productivity growth but not of absolute productivity level. Current price weights do yield a valid index of absolute productivity but one that tends to be equal for all industries because of the general equilibrium mechanism that reallocates resources from low-productivity to high-productivity industries.

Energy-production subsidies are, paradoxically, shown to be likely to increase U.S. dependence on imported oil. Standard studies of net energy yields are shown to be seriously biased upward for two reasons. First, many omit indirect energy inputs, which, our input-output calculation shows, probably causes large errors. Second, those studies all omit the energy opportunity costs of nonenergy inputs (e.g., the fuel substituted elsewhere for the labor used to produce energy). We prove that, absent externalities, any fuel-output subsidy which causes an otherwise unprofitable expansion must yield an incremental fuel output smaller than the increment in energy input plus the energy opportunity costs of other inputs.