Birth rates are falling -
almost no country in the world has a higher birth rate than it did 50 years
ago. The world population hit the first billion in roughly 1804 - then it took
another 123 years, to 1927, to reach the second billion. Then the world hit
three billion by 1959, then four billion by1974, then five billion by 1987,
then six billion by 1999, and it reached 7 billion in 2011.
Birth rates are falling, in part because of birth control, in part because of increased prosperity, and in part because of female emancipation. But there are three less obvious reasons too.
The first is decreasing infant mortality. Yes, that's right - it is counterintuitive, but the lower the levels of infant mortality, the fewer children are born on average. This is because if a woman thinks there is a good chance that her children will die young, she will have more of them, whereas if she feels there is a good chance her children will survive, she will have fewer of them.
The second is economic freedom. The freer the society is, the more liberty for the individuals, and the less they are a slave to their reproductive cycles.
And the third is more people are gravitating towards cities, and cities with intense competition for housing can work against larger families. World cities already contain over 3.5 billion people (nearly half the world's population), and that figure is predicted to rise to 5 billion by 2025. What's also interesting is that despite half the world's population living in cities, they only take up 3% of the planet's land area.
