Danish economist Ester Boserup, working for the FAO, did historical research finding that as the human population increased, people had long found ways to increase food production. Malthus had been wrong even about the preindustrial era, she found.94 In 1981, the Indian economist Amartya Sen published a book showing that famines occur not because of lack of food but due to war, political oppression, and the collapse of food distribution, not production, systems.