Birth rates are falling around the world, and while this might seem like nothing new, as it's been the case in developed countries for quite some time,

the number of newborns in Japan fell 5% last year, and birth rates hit record lows in England and the United States too.

The thing that's interesting is that we're seeing declining birth rates everywhere and the standard explanations that you've heard in the past don't really hold up.

The first contraceptive pill was approved by the FDA in the United States in 1960.

And over the next 20 years, the average number of children born to American women halved

from almost 4 to 2.

The pill had a major impact on society and culture.

It contributed to a sharp increase in female college attendance and graduation rates.

Over that 20-year period, the number of marriages only fell slightly.

The fertility rate, which is the expected number of children born per woman in her childbearing

years, sits at 1.44 children per woman today in the UK, and 1.64 children per woman today in the United States.

The replacement fertility rate, which would keep the population steady, is 2.1 births per

woman in the developed world, but it can be as high as 3.5 in undeveloped countries because of

higher mortality rates. There are a lot of reasons given

for the falling birth rates in wealthy countries, most obviously increased access to contraception,

but also improved education and career opportunities for women, the rising cost of living

and raising children, and changing societal values and family structures.

The interesting thing though is that birth rates are collapsing everywhere, not just in the

developed world. Tunisia, Turkey, Tamil Nadu, Guatemala and Mexico are all experiencing

similar declines. According to research from my colleague Alice

Evans at King's College London, Turkey has a lower birth rate than the UK does, and Mexico

has a lower birth rate than the United States. When you look at the factors that can be blamed,

...