People who live in democracies live longer on average, and are healthier, than people in dictatorships, even when you account for differences in wealth. It's not (mostly) because people are less likely to be shot or tortured in democracies, although that's true, but because democracies tend to spend more on health care.

Disturbingly, in recent years people who've never experienced anything else have started to doubt the value of government for the people, by the people, of the people. Although it sometimes gets exaggerated in news reports, citizens of democracies have increasingly started to endorse survey statements touting the superiority of strong but unaccountable leaders over elected parliaments.

If you're among those people who think dictatorships are more efficient, and therefore will deliver more of what you want, Professor Thomas Bollyky of the Council on Foreign Relations has something to say. He analyzed data from 170 countries from 1970-2015 recording the type of governance, life expectancy and deaths from different causes, per capita gross domestic product (GDP), and health expenditure. Assessing the extent to which a nation is democratic is harder than the other measures, but Bollyky's dataset took into account that there is more to democracy than holding an election. Nations where opposition parties cannot campaign safely were rated down.

Most rich nations over this period were democracies, and while this is almost certainly not a coincidence, Bollyky and co-authors of a paper in The Lancet were keen to distinguish between the effects of wealth and people power.

Adoption of sustained democracy boosts life expectancy at the age of 15 by 3 percent, Bollyky found – around two years in most places. This was achieved primarily through a reduction in cardiovascular disease and transport injuries, although whether there are fewer car-crashes, or hospitals are better equipped to save people's lives, is unclear. For both, democracy matters more than a nation's wealth.

Democracies spend more on health care than dictatorships of similar income, which seems to be the main reason for the performance gap. The difference is largest for conditions expected to account for more deaths in the future.

Several previous papers have looked at the health implications of democratic governance, but only for children under the age of 5. These reached mixed conclusions.

Bollyky's work implies we should be valuing our democracies more if we're lucky enough to live in one. Even when election candidates don't inspire us, they're still better than the alternative, assuming you prefer a long and healthy life to a short and sickly one. The paper also concludes that democratic governance is a global health issue. Organizations seeking to reduce mortality in the most impoverished parts of the world may want to take that into account.