Lecture 7 theories & consequences of population change. Population growth theory-malthus: thomas robert malthus (1766-1834, an essay on the principle of population (1798, malthus" argu(cid:373)e(cid:374)t, population increases in an exponential fashion, used to have more food than population, but now population is exceeding food. No, there was never a particular shortage on food: agricultural productivity. Industrial revolution resulted in huge increase on food supply: contraception, ne(cid:448)er a(cid:374)ticipated pre(cid:448)e(cid:374)tati(cid:448)e (cid:862)checks(cid:863) (cid:449)ould (cid:449)ork, people began to have fewer children and fertility rates dropped. Fertility transition a model to explain changes in population due to social/cultural and economic processes that affect levels of fertility: more developed world: 19th and early 20th century, economic growth. Less developed/developing world: late 20th century and today. Fertility is dropping: unrelated to economic growth, more a social and cultural change. Social and cultural change: contraceptive use: around 61, contraceptive methods: around 55, comparable rates to more developed world: role of public health/family planning education.