Everywhere in the world women live longer than men - but this was not always the case. The available data from rich countries shows that women didn't live longer than men in the 19th century. What's the reason why women live longer than men? Why has this advantage gotten larger over time? The evidence is limited and we have only limited answers. While we are aware that there are behavioral, biological and environmental factors that all play a role in women living longer than men, we do not know the extent to which each factor plays a role.

Independently of the exact amount of weight, we are aware that a large portion of the reason why women live longer than men today, but not in the past, has to have to do with the fact that certain fundamental non-biological factors have changed. What are the factors that are changing? Some are well known and relatively straightforward, like the fact that men smoke more often. Some are more complex. For example, there is evidence that in rich countries the female advantage increased in part because infectious diseases used to affect women disproportionately a century ago, so advances in medicine that reduced the long-term health burden from infectious diseases, especially for survivors, ended up raising women's longevity disproportionately.

Everywhere in the world women tend to live longer than men
The first chart below shows life expectancy at birth for Inf-energy.com/?option=com_k2&view=itemlist&task=user&id=923822 (www.imagineonline.net) men and women. We can see that every country is above the diagonal line of parity - this means that in all countries that a baby girl can be expected to live longer than a newborn boy.1

This chart shows that, even though women enjoy an advantage everywhere, cross-country differences are often significant. In Russia, women live for 10 years longer than males. In Bhutan, the difference is less than half a calendar year.

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In countries with high incomes, the longevity advantage for women was not as great.
Let's examine the way that female advantages in terms of longevity has changed over time. The next chart compares the male and female lifespans at birth in the US during the time period between 1790 and 2014. Two points stand out.

There is an upward trend: Men and women in the US live a lot, much longer than they did a century ago. This is in line with historical increases in life expectancy everywhere in the world.

The second is that there is an ever-widening gap: female advantage in life expectancy used to be very small however it increased dramatically during the last century.

If you select the option "Change country in the chart, you can verify that these two points are also applicable to the other countries with available information: Sweden, France and the UK.