Nicholas Kristof has a Twitter link to a paper by Charles Kenny, a senior economist at the World Bank, who has some interesting ideas contra the Malthusian model of population dynamics, which held that population growth is determined by incomes and that land capacity set fixed constraints.
Kenny writes inter alia in Is Anywhere Stuck in a Malthusian Trap? Kyklos, Vol. 63, Issue 2, pp. 192-205, May 2010 as follows:
The key features of the Malthusian model are that (i) income determines population growth, with rising wages increasing survival rates and (ii) there is a vital factor of production (land) which is fixed, implying decreased returns to scale for all other factors. The equilibrium state in such a model is a population living on subsistence incomes. The country-level analysis in this paper suggests that (i) the link between income and population growth is (almost) everywhere broken and (ii) there is little evidence of declining returns to scale because of constraints imposed by land carrying capacity anywhere. Population dynamics are being driven by non-income factors in a manner that is reducing population growth rates everywhere. At the same time, output is increasing everywhere, in a manner inconsistent with significantly declining returns to scale based on land being a vital factor of production.
. . .
Malthus himself, in his Political Economy, argued that the best way to decrease birth rates was through "civil and political liberty, and education" which would encourage poor people to seek the "means of being respectable, virtuous and happy" through smaller families. He may have been partially right for the wrong reasons.... [read the article for those]
...Malthus argued that the secret to progress was prudence in personal affairs rather than institutional change, but while prudence in personal affairs may be part of the story ... this very prudence appears to have its roots in the spread of education and health technologies that have required significant institutional change...."This is a must read.
Kenny, Charles, Is Anywhere Stuck in a Malthusian Trap?. Kyklos, Vol. 63, Issue 2, pp. 192-205, May 2010. Available at SSRN: http://ssrn.com/abstract=1587125 or http://dx.doi.org/10.1111/j.1467-6435.2010.00469.x