Capital in the Twenty-First Century

by Thomas Piketty

To recap: the inequality r > g is a contingent historical proposition, which is true in some periods and political contexts and not in others. From a strictly logical point of view, it is perfectly possible to imagine a society in which the growth rate is greater than the return on capital—even in the absence of state intervention. Everything depends on the one hand on technology (what is capital used for?) and on the other on attitudes toward saving and property (why do people choose to hold capital?). As noted, it is perfectly possible to imagine a society in which capital has no uses (other than to serve as a pure store of value, with a return strictly equal to zero), but in which people would choose to hold a lot of it, in anticipation, say, of some future catastrophe or grand potlatch or simply because they are particularly patient and take a generous attitude toward future generations. If, moreover, productivity growth in this society is rapid, either because of constant innovation or because the country is rapidly catching up with more technologically advanced countries, then the growth rate may very well be distinctly higher than the rate of return on capital. In practice, however, there appears never to have been a society in which the rate of return on capital fell naturally and persistently to less than 2–3 percent, and the mean return we generally see (averaging over all types of investments) is generally closer to 4–5 percent (before taxes). In particular, the...