Almost everyone knows about the strong productivity gains of American farmers. This has made it possible for far fewer of them to feed many more of us. In the last 100 years, the proportion of the labor force engaged in agriculture has fallen dramatically, from 42.3 percent in 1890 to 1.8 percent in 1990 (Table 1).
At the time of the American Revolution, 95 percent of workers were farmers. It took 19 farmers to feed themselves and one other. The agricultural population has fallen steadily in absolute numbers while farm output has skyrocketed. It is not surprising that all this takes place on much less land. Mechanized farming also works best on flat lands. The hills of New Hampshire are no longer farmed because it is no longer economic. Research by Frey (1995) documents the fact that U.S. cropland use peaked in 1930 (Table 2).
Land used for recreation, forests and wildlife has been increasing even while the cities have been expanding (Table 3). In any event, the urbanized areas' share of total land use in 1992 was less than 4.76 percent (refers to "developed" which "includes all urban and built-up areas in units of 10 acres or greater and rural transportation;" Statistical Abstract 1996, Table 365).
With respect to food and the world's population, Simon (1996, 5) says it best: "Contrary to popular impression, food production per capita has been increasing for the half-century since WWII, the only decades for which we have acceptable data. We also know that famine has progressively diminished for at least the past century. Average height has increased in developed countries in recent centuries, a sign that people are eating better. And there is compelling reason to believe that human nutrition will continue to improve into the indefinite future, even with continued population growth." In fact, population "bomb" doomsday scenarios were not only overblown but misdirected. Not only is world population growth slowing, it will probably start to decline relatively soon: "the world's population rather than continuing to increase will in our lifetimes peak, and then commence an indefinite decline in the generations immediately ahead" (Eberstadt 1997, 3). The United Nations' "low variant" projection, currently the most likely, predicts that the world population will peak around 7 billion around 2030, and then begin a long descent. A "birth dearth" that is likely to spread has been reported in developed as well as in 27 developing countries. Food does not reach all of the world's people because of war, inadequate redistribution mechanisms and inept or corrupt political practices in some countries. At the global scale, however, food is abundant and people are scarce, precisely the opposite of the popular view. More than 20 years ago, the late Roger Revelle estimated that if best-practice technology was adopted, the existing arable land in the world could feed 98 billion people. We do not know whether his numbers stand up to contemporary scrutiny, but they certainly accommodate a large margin of error. Higher standards of living are the proof that the terms of trade have shifted in labor's favor; relative scarcities have changed in ways that favor more consumption. The future of biotech and superior crops and larger harvests will only make things better. The demand for croplands will continue to fall. This prospect has been enhanced by the 1996 Federal Agricultural Improvement Reform Act (FAIR) which gradually eliminates Federal subsidies for keeping land idle, allowing farmers to plant whatever they like. Unfortunately, State subsidies to agriculture continue to flourish.
Data on these and other scarcity trends have been available since at least 1963 when Barnett and Morse published Scarcity and Growth. Not only food, but most resources are becoming much less scarce. Inventiveness and technological advance, powered by markets, deserve the credit. This illustrates once again how much faulty models cost us. It is commonplace to agree that the Earth and everything on it is "finite". Most go on to conclude that humankind must, therefore, be approaching the time when the cupboards will, indeed, be empty. Yet, simple economic analysis suggests that increasing scarcity pushes up prices. And, given enough time, all kinds of consequences follow. There are many responses to higher prices, including substitutions (conservation or even recycling efforts by consumers and producers) and expansive efforts by sellers. But the most important response is inventiveness (in pursuit of wealth, glory, a place in heaven or whatever) which pushes back the effects of scarcity. In poultry production, for example, the "combination of good management and scientific development has produced the same amount of product, of higher quality, in half the time, using less barn space, less land, less electricity, less propane heat, and close to half as much food" ( Zinsmeister 1993, 94). "Finiteness" (not to mention appeals to the Second Law of Thermodynamics) becomes a meaningless concept in the face of continuously expanding opportunities.
The evidence is abundant and clear that the real world works this way. Known reserves of most natural resources keep growing and their prices keep falling, even as the world's demand expands. The most important scarcity is human talent. This is precisely why standards of living have been rising. It is when this mechanism is misunderstood that we get costly initiatives like 1970s-style energy policy. Blunders like this have consequences. They stifle the material advance of the human condition.