Capital in the Twenty-First Century

by Thomas Piketty

It was this lecture, published in 1955 under the title “Economic Growth and Income Inequality,” that gave rise to the theory of the “Kuznets curve.”

The technological convergence process may be abetted by open borders for trade, but it is fundamentally a process of the diffusion and sharing of knowledge—the public good par excellence—rather than a market mechanism.

On August 16, 2012, the South African police intervened in a labor conflict between workers at the Marikana platinum mine near Johannesburg and the mine’s owners: the stockholders of Lonmin, Inc., based in London. Police fired on the strikers with live ammunition. Thirty-four miners were killed.1 As often in such strikes, the conflict primarily concerned wages: the miners had asked for a doubling of their wage from 500 to 1,000 euros a month. After the tragic loss of life, the company finally proposed a monthly raise of 75 euros.

From 1900 to 1980, 70–80 percent of the global production of goods and services was concentrated in Europe and America, which incontestably dominated the rest of the world. By 2010, the European–American share had declined to roughly 50 percent, or approximately the same level as in 1860. In all probability, it will continue to fall and may go as low as 20–30 percent at some point in the twenty-first century. This was the level maintained up to the turn of the nineteenth century and would be consistent with the European–American share of the world’s population (see Figures 1.1 and 1.2). In other words, the lead that Europe and America achieved during the Industrial Revolution allowed these two regions to claim a share of global output that was two to three times greater than their share of the world’s population simply because their output per capita was two to three times greater than the global average.

In theory, the fact that the rich countries own part of the capital of poor countries can have virtuous effects by promoting convergence. If the rich countries are so flush with savings and capital that there is little reason to build new housing or add new machinery (in which case economists say that the “marginal productivity of capital,” that is, the additional output due to adding one new unit of capital “at the margin,” is very low), it can be collectively efficient to invest some part of domestic savings in poorer countries abroad. Thus the wealthy countries—or at any rate the residents of wealthy countries with capital to spare—will obtain a better return on their investment by investing abroad, and the poor countries will increase their productivity and thus close the gap between them and the rich countries. According to classical economic theory, this mechanism, based on the free flow of capital and equalization of the marginal productivity of capital at the global level, should lead to convergence of rich and poor countries and an eventual reduction of inequalities through market forces and competition.

In essence, all of these countries themselves financed the necessary investments in physical capital and, even more, in human capital, which the latest research holds to be the key to long-term growth.

In 2013–2014, for example, global economic growth will probably exceed 3 percent, thanks to very rapid progress in the emerging countries. But global population is still growing at an annual rate close to 1 percent, so that global output per capita is actually growing at a rate barely above 2 percent (as is global income per capita).

It is important to understand that we are just emerging from this period of open-ended demographic acceleration. Between 1970 and 1990, global population was still growing 1.8 percent annually, almost as high as the absolute historical record of 1.9 percent achieved in the period 1950–1970. For the period 1990–2012, the average rate is still 1.3 percent, which is extremely high.

I will show that the intuition concerning the effects of strong demographic growth can to a certain extent be generalized to societies with very rapid economic (and not just demographic) growth. For example, in a society where output per capita grows tenfold every generation, it is better to count on what one can earn and save from one’s own labor: the income of previous generations is so small compared with current income that the wealth accumulated by one’s parents and grandparents doesn’t amount to much. Conversely, a stagnant or, worse, decreasing population increases the influence of capital accumulated in previous generations. The same is true of economic stagnation.

Take the wealthy countries as an example. In Western Europe, North America, and Japan, average per capita income increased from barely 100 euros per month in 1700 to more than 2,500 euros per month in 2012, a more than twentyfold increase.10 The increase in productivity, or output per hour worked, was even greater, because each person’s average working time decreased dramatically: as the developed countries grew wealthier, they decided to work less in order to allow for more free time (the work day grew shorter, vacations grew longer, and so on).

This is not a minor point: not only do these two sectors account for more than 20 percent of GDP and employment in the most advanced countries—a percentage that will no doubt increase in the future—but health and education probably account for the most tangible and impressive improvement in standards of living over the past two centuries. Instead of living in societies where the life expectancy was barely forty years and nearly everyone was illiterate, we now live in societies where it is common to reach the age of eighty and everyone has at least minimal access to culture.

In practice, when we think of the property owned by churches over the centuries, or the property owned today by organizations such as Doctors without Borders or the Bill and Melinda Gates Foundation, it is clear that we are dealing with a wide variety of moral persons pursuing a range of specific objectives.

if wealth is accumulated primarily for life-cycle reasons (saving for retirement, say), as Modigliani reasoned, then everyone would be expected to accumulate a stock of capital more or less proportional to his or her wage level in order to maintain approximately the same standard of living (or the same proportion thereof) after retirement. In that case, inequality of wealth would be a simple translation in time of inequality of income from labor and would as such have only limited importance, since the only real source of social inequality would be inequality with respect to labor.

The very high concentration of capital is explained mainly by the importance of inherited wealth and its cumulative effects:

For example, many people belong to the upper class in terms of labor income but to the lower class in terms of wealth, and vice versa. Social inequality is multidimensional, just like political conflict.

In the most egalitarian countries, the bottom 50 percent receive nearly twice as much total income as the top 10 percent (which some will say is still too little, since the former group is five times as large as the latter), whereas in the most inegalitarian countries the bottom 50 percent receive one-third less than the top group.

In the poorer half of the top decile, we are truly in the world of managers: 80–90 percent of income comes from compensation for labor.7 Moving up to the next 4 percent, the share of income from labor decreases slightly but remains clearly dominant at 70–80 percent of total income in the interwar period as well as today (see Figures 8.3 and 8.4). In this large “9 percent” group (that is, the upper decile exclusive of the top centile), we find mainly individuals living primarily on income from labor, including both private sector managers and engineers and senior officials and teachers from the public sector. Here, pay is usually 2 to 3 times the average wage for society as a whole: if average wages are 2,000 euros a month, in other words, this group earns 4,000–6,000 a month.

For example, in France, the share of income from capital in 1932 as well as 2005 is 20 percent at the level of “the 9 percent” but increases to 60 percent in the top 0.01 percent. In both cases, this sharp increase is explained entirely by income from financial assets (almost all of it in the form of dividends).