Viewing a longer segment of American history, from 1840 to 1960, Simon Kuznets has illuminated the phenomena of growth from a perspective that permits comparison with the records of a number of other countries. During that 120-year span the American population grew at an average annual rate of about 2.2 percent, gnp at 3.6 percent, output per capita at 1.6 percent, and product per worker at 1.4 percent. As a result of these growth rates, the population in 1960 was about 10.5 times as large as in 1840, the labor force almost 13 times, per capita product over 6 times, and product per worker over 5 times as large.

Surviving statistical data from the United Kingdom, France, Germany, Russia, and Japan range from 79 years for Japan to 117 years for the United Kingdom. The first result of a comparison between these countries and the United States is that the annual rate of growth of population in the latter was much higher than in any of the others. Compared with 2.2 percent in the United States, the rates of others ranged from 1.2 percent for Japan to 0.2 percent for France. Except for Japan alone, population growth rates in all the others were no more than half that of the United States.

Second, the annual rates of growth of product per capita for the United States and for the European countries were not greatly different. (The rates range from 1.9 percent for Russia, for a period reaching back to 1760, to 1.2 percent for the United Kingdom, back to 1841.) The American rate was 1.6 percent. The Japanese rate, for the period 1880–1960, was distinctly higher, 2.8 percent. Were data available to permit comparisons between the United States and these countries over the same length of time – all the way back to 1840—the averages for the other countries would be lower, including that of Japan. Finally, the rate of growth of gnp in the United States was higher than for the European countries, by amounts ranging from one-fifth to twice as high. This result naturally follows from the fact that the United States’ roughly equivalent rate of growth of per capita product was combined with a much higher rate of growth of population.

The American performance was exceptional. In his Essay on the Principle of Population (1798) Thomas Malthus offered a grim assessment of the consequences that would follow an increase in output. Population would respond by growing and would consume the additional output, reducing the level of living to what it had been before. The pressure of population on resources seemed relentless to Malthus, and he expected that war, pestilence, and starvation would provide the means of reducing it. American history offered testimony of a different kind: it was possible to have it both ways – more people and more resources, too. Technological advances would enable developed countries throughout the world to respond similarly to Malthus’s predictions.

In the closing decades of the twentieth century the American economy, as before, alternated between periods of expansion (for example, 1963–1968, 1976–1980, 1983-) and contraction (for example, 1969–1970, 1974–1975, and 1980–1982), without, however, sinking into a deep and prolonged depression like those of the 1870s and 1930s (although some of the contractions – now called recessions – were severe, for example, those of 1974–1975 and 1980–1982). Built-in stabilizers put in place by President Franklin D. Roosevelt’s New Deal in the 1930s – for example, old age and survivors’ and unemployment insurance – provided cushions during periods of falling demand. The uses of monetary and fiscal policies, too, were far better understood than before.