The World Bank's index of food prices increases by 140 percent from January 2002 to the beginning of 2008, and a full 75 percent just since September 2006. This highly unusual explosion of food prices has been seized upon by neo-Malthusians as the beginning of a day of reckoning due to the collision between he limited capacity of the earth to produce foods and the growing demand for food and other commodities induced by rapid world population and income growth. Malthusians have turned out to be wrong in the past when they extrapolated from events like food price inflation to prophesies about world catastrophe-witness the embarrassingly wrong predictions in Paul Ehrlich's The Population Bomb about the impending mass world starvation in the 1970's due to what he considered vastly excessive world population growth. They are also wrong about this current food price rise because it has nothing to do with population growth, and is only a little related to the rapid expansion in world incomes in recent years.
Rather, the boom in petroleum prices and subsidies to ethanol and other biofuels are the most important forces explaining the recent increase in food prices. Both the sharp run up in oil prices, and the continuing subsides to ethanol production in the United States, and to a lesser extent Europe, induced an increasing diversion of corn from feed and human consumption to the production of biofuels. The main goal of the diversion has been to produce more ethanol as a substitute for gasoline. During the past year, one quarter of American corn production, and 11 percent of global production, was devoted to biofuels, and the US contributes a lot to the world corn market. The growth in demand for biofuels explains why acreage was shifted from other grains to corn-the acreage devoted to corn in the United States increased by over twenty percent in 2007-8, while that devoted to soybean production declined by more than fifteen percent. The reallocation of production away from other grains explains the rapid price increases for wheat, soybeans, and rice as well as for corn.
The huge increase in petroleum prices also pushed up the cost of producing foods, and hence food prices, since energy is an important input in the production of fertilizers and agricultural chemicals. Other factors affecting the rise in food prices include the drought in Australia in 2006-07 that cut world grain production during those years, and the fall in the value of the dollar that may have increased the dollar value of foods and other commodities.
The Malthusian forces of population and income growth ontributed only a little to explaining the big increase in grain prices since 2002. The large rise of world food prices came after food prices had been either stable or declined for many years.
Although incomes in China and India, countries that account for almost 40 percent of the world's population, did grow rapidly during this decade as well as during the 1990's, global consumption of corn, wheat, and rice grew more slowly since 2000 than during the five years earlier. To be sure, the slower growth in consumption is partly the result of the rapid increase in grain prices. However, if an unusually large increase in world wide demand for grains to use as feed for animals and for human consumption explained the rapid increase in these prices, consumption should have grown more rapidly during the later period, even after adjusting for any induced increase in grain prices.
Some countries, including Argentina, India, Russia, and Vietnam, have responded to the sizable run up in food prices by severely restricting, or heavily taxing, food exports. By reducing exports of rice and other grains, these policies lowered the supply of these grains to importing countries, and helped bid up world prices. At the same time, however, these restrictions kept a lid on domestic prices of rice and other grains by diverting some supplies to domestic markets.
Governments in countries that restricted food exports usually responded to urban riots and other domestic disturbances, such as those in Egypt, Haiti, and Vietnam, that were protests against food price increases. The restrictions on food exports reflect the general tendency of governments in poorer countries to favor urban consumers over farmers. Since food accounts for a large fraction of household spending in poorer countries-over 70 percent in poor households- sharp food price increases would cut by a lot the purchasing power of poorer urban consumers. On the other hand, farmers are hurt by restrictions on their food exports since they get lower domestic prices than they could get on the world market. Restrictions of food exports also lower the efficiency and overall incomes of the countries imposing them since a lid on domestic food prices discourage farmers from increasing their food production at a time when world food prices have been rising at a fast pace.
Some analysts have justified these export restrictions as a way to combat the effect of rising food prices on poverty. However, poverty is much more prevalent among rural than urban families in developing countries like China, Egypt, India and Vietnam. So restrictions on food exports in developing nations not only lower the efficiency of their food production, but also usually raise inequality and overall poverty. The greater political clout of urban households in developing nations is the pressure behind the support for these inefficient and inequitable export restrictions, just as the greater political clout of farmers in developed nations maintains the inefficient, and probably energy-wasteful, ethanol subsidies in the United States and other rich countries.