1. Malthusian Population Theories
- Malthus argued that "Population grow at a rate that exceeds available food supply"
- Population can survive only because of positive checks on population growth. That is, in mortality due to famines, epidemics, wars and natural causes, preventive checks e.g. abstinence and contraception.
2. Neo-Malthusian
- Contemporary follower of the Malthus ideas
- They focus more on the health and mortality consequences of a changing environment e.g. Each argue that the impact on the environment is a function of population size, level of affluence and technology.