ON October 31, 2011 the world’s population will top seven billion. That’s according to expert opinion and a recent article in Nature.
Writing in 1798, when there were less than one billion people on planet earth, Thomas Malthus suggested that misery, vice and poverty would keep population in check. 
Malthus was wrong.
Where there is most poverty, population growth is accelerating, while in rich countries population growth is slowing. The average number of children per woman in the world’s poorest countries is 4.5, compared to 1.7 for developed countries.
It is small increases in wealth and education that can lower fertility and are likely to result in a slowing in the world’s population growth.
1. Jeff Tollefson. Seven billion and counting. Nature 478, 300 (2011)
2. Thomas Malthus. An Essay on the principle of population. Thomas Malthus, 1798