Kuczynski in his view was nothing more than a manipulator, a charge that was wide of the mark." Also in 1939, Keynes took the side of the bourgeois economists, calling the stability of the capital-labor split one of the best established regularities in all of economic science." This assertion was hasty to say the least, since Keynes was essentially relying on data from British manufacturing industry in the 1920s, which were insufficient to establish a universal regularity In textbooks published in the period 1950-1970(and indeed as late as 1990), a stable capital labor split is generally presented as an uncontroversial fact. but unfortunately the period to which this supposed law applies is not always clearly specified. Most authors are content to use data going back no further than 1950, avoiding comparison with the interwar period or twentieth century, much less with the eighteenth and nineteenth centuries. From the 1990s on, however, numerous studies mention a significant increase in the share of national income in the rich countries going to profits and capital after 1970, along with the concomitant decrease in the share going to wages and labor. The universal stability thesis thus began to be questioned. and in the 2000s several official reports published by the Organisation for Economic Cooperation and Development (OECD) and International Monetary Fund (IMF) took note of the phenomenon (a sign that the question was being taken seriously The novelty of this study is that it is to my knowledge the first attempt to place the question of the capital labor split and the recent increase of hare of national income in a broader historical context by focusing on the evolution of the capital/income ratio from the eighteenth century until now. The exercise admittedly has its limits, in view of the imperfections of the avail- able historical sources, but I believe that it gives us a better view of the major sues and puts the question in a whole new light.