Overpopulation is not the necessary and inevitable consequence of high density of population. Tiny Monaco, a principality in southern Europe about half the size of New York's Central Park, has a crude density of nearly 20,000 people per square kilometer (50,000 people per sq. mi). Mongolia, a sizable state of 1,565,000 square kilometers (604,000 sq. mi.) between China and Siberian Russia, has 1.5 persons per square kilometer (4 per sq. mi.); Iran, only slightly larger, has 37 per square kilometer. Macao, an island ossession of Portugal off the coast of China, has more than 26,000 persons per square kilometer; the Falkland Islands off the atlantic coast of Argentina count at most 1 person for every 6.5 square kilometers of territory. No conclusions about conditions of life, levels of income, adequacy of food, or prospects for prosperity can be drawn from these density comparisons.

Overpopulation can be equated with levels of living or conditions of life that reflect a continuing imbalance between numbers of people and carrying capacity of the land. One measure of that imbalance might be the unavailability of food supplies sufficient in caloric content to meet individual daily energy requirements or so balanced as to satisfy normal nutritional needs. Unfortunately, dietary insufficiencies - with long-term adverse implications for life expectancy, physical vigor, and mental development - are most likely to be encountered in the developing countries, where much of the population is in the younger age cohorts.

If those developing countries simultaneously have rapidly increasing population numbers dependent on domestically produced foodstuffs, the prospects must be for continuing undernourishment and overpopulation. Much of sub-Saharan Aftica finds itself in this circumstance. Africa's per capita food production decreased 25% between 1960 and 1990, and a further 30% drop is predicted over the following quarter century as the popluation-food gap widens. Egypt already must import more than half the food it consumes. Africa is not alone. The international Food and Agriculture Organization (FAO) projects that by A.D. 2000, no less than 65 separate countries with some 30% of the population of the developing world will be unable to feed their inhabitants from their own national territories at the low level of agricultural technology and inputs apt to be employed. Even rapidly industrializing China, an exporter of grain until 1994, has become a net grain importer; if its massive and growing population continues its new dependence on imported basic foodstuffs, world grain surpluses and food aid flows will be seriously affected.