Le due leggi fondamentali del capitalismo: da Marx e Sraffa, Harrod e i post-keynesiani a Piketty

Piketty’s explanation for the tendency towards greater inequality in the capitalist distribution of income and its growth is based on the “two fundamental laws of capitalism”. The “first fundamental law” is largely the same as well-known relationships developed by Karl Marx and Piero Sraffa. On the one hand, Piketty’s relationship between capital and income corresponds to Sraffa’s maximum rate of profit in the “Standard system”. On the other hand, both Marx and Piketty focus on periods of a growing ratio of capital to income. A growing ratio of capital to income is caused by a rate of profit higher than the growth rate of the economic system. However, this is a sufficient condition for the ratio to grow only in what here is called a “pure classical model”. In models characterized by a less strong class division of the economy, the ‘Cambridge equation’ applies. The “second fundamental law” is equivalent to Harrod’s warranted growth rate. The second law must be developed in connection with the Cambridge post-Kenesyan models, to avoid a paradoxical reduction in inequality, when the analysis is based on average rates of profit and savings. The different capacity to earn profits and save of capitalists and workers must be developed, in order to show that the capitalist economy is characterized by substantial inequality in the distribution of income. Piketty’s explanation of the raise of inequalities needs a precise definition of the economic power of the different social classes.