I remember, several years ago reading a short piece of speculative fiction which postulated that China would go to war over access to women. Generations of female infanticide would leave the country with a severe gender imbalance. Hoards of men would be unable to find a wife, would become violent, and would lead their country into bitter conflicts with other countries in order to capture their women.

A simplistic approach, perhaps. There are many perceived consequences of an unchecked male population growth. But gender imbalance stemming from female infanticide is a real problem around the world.

The Indian Census has released some very detailed statistics for the country's population. This chart shows the male:female ratio in Dehli.

Now, there are several reasons why there may be fewer women than men in Delhi. Economic migration may play a part for example. What we can look at with some accuracy is the birth rate.

In most human societies, more boys are born than girls. In 2011, the global sex ratio was 984 females per 1,000 males.

In India, the rate is 940.

In Delhi? It's 866.

In rural Delhi? 809.

Delhi has 1.2 million more men than women.

By way of comparison, In the UK as a whole there are 970 males to every 1,000 females (according to the ONS mid-2007 population estimates). Of course, the UK doesn't have an exemplary record when it comes to sex crimes.

There are many factors to the continued female harassment around the world. I don't want to appear to be an apologist for sexual violence, or single this out as the sole cause for these shameful crimes. However, I can't help but wonder whether populations with such unhealthy sex ratios provide an environment which fosters a truly terrible attitude to women.