values and prices are strongly correlated. Drawing on their experiences in the controversy over Marx's value theory, some proponents of the TSSI have also been active in the movement for pluralism in economics, and they have critiqued, and argued for the reform of, the interpretive methods employed in Marxian economics. Proponents of the TSSI include, among others, Guglielmo Carchedi, John Ernst, Alan Freeman, Paolo Giussani, Andrew Kliman, Eduardo Maldonado-Filho, Ted McGlone, Nick Potts and Alejandro Ramos Martinez. Significance of temporal and single-system The words "temporal" and "single-system" in the title of the TSSI refer to the two key differences between it and the interpretation of Marx's value theory derived from Ladislaus von Bortkiewicz that at one time dominated academic Marxist economics. According to the Bortkiewiczian interpretation, prices and values of inputs into the production process are, in Marx's theory, determined simultaneously with the prices and values of the outputs that later emerge from the production process. Thus, inputs' prices (or values) and outputs' prices (or values) are necessarily equal. In contrast, the TSSI is "temporal" or non-simultaneous, holding that prices (and values) of inputs and outputs in Marx's theory need not be (and generally are not) equal. Second, according to the Bortkiewiczian interpretation of Marx's value theory, values and prices constitute two distinct and independent "systems". With respect to relative magnitudes, prices do not depend on values, and values do not depend on prices. Prices of outputs depend on the prices of the inputs used to produce them, while values of outputs depend on the values of the inputs used to produce them. In contrast, the TSSI is a "single-system" interpretation since it holds that, in Marx's theory, (a) prices of outputs depend in the aggregate on the so-called "value rate of profit" (the ratio of surplus-value to capital invested), while (b) businesses' investments of capital value, and thus the values of the outputs produced, depend partly on the prices of the inputs acquired by means of these investments. Value and price are therefore determined interdependently, though they remain distinct. Proofs of Marx's inconsistencies "Okishio's theorem", a result produced by the Japanese Marxian economist Nobuo Okishio in 1961, was widely regarded as having disproved Marx's law of the tendency of the rate of profit to fall, but TSSI authors have shown that Marx's rate of profit (as they interpret it) can fall in circumstances in which Okishio's theorem says that