Thomas Malthus posited in the late 1700s that exponential population growth would soon outstrip food supplies; he assumed that food supplies would grow linearly or hit a maximum land capacity. Two centuries later, people continue to offer similar pessimistic warnings concerning the global food supply, despite little evidence for such a crisis. Statistics from the United Nations actually show food per capita growing substantially, even in densely populated regions. Only Africa remains stagnant, and as Chapter 7 noted, the problems there come from larger economic challenges. This increase occurs despite falling food prices, which diminish the economic incentive to produce more food. Staple foods like rice and wheat cost less than half what they did in the 1950s, thanks in large part to techniques that allow a vastly improved yield per hectare. Many regions could improve production even more by adopting existing technology. Given these facts, the persistence of hunger and malnourishment is shocking.

Although food supply itself does not provide a good argument for reducing world population, Sen asserts that continued population growth would self-evidently pose some kind of problem in the future, such as urban overcrowding or environmental strain. Although fertility rates are declining, there is considerable debate about how fast they are declining and whether they will naturally continue to do so or whether public authorities need a coercive approach to force women to have fewer children.