Deaths came down during the Great Recession in Europe, particularly in the places that suffered the most. Declines in pollution from reduced industrial activity are one likely explanation. 24Novembers/Shutterstock

Public health experts aren't known for recommending governments induce recessions to extend lives. Wealthier nations have longer life expectancies, so death rates are expected to go up when the economy goes bad. Yet, sometimes the opposite is true.

A study of 15 European countries before and during the 2008 Global Financial Crisis found the worse the economy got, the fewer people died. The reasons remain uncertain and explaining the effect could lead to important policy changes.

Money can’t always buy you health, but on an individual level, higher incomes are associated with longer lives. Wealth pays for better health care, more nutritious diets, and a house in a “walkable” suburb. The comfortably off are also more likely to feel they have something to live for. After centuries of improvement, American life-expectancy has stalled, which has been attributed to “deaths of despair”, including not just suicide, but drug and alcohol addiction, concentrated among those without work or in low-income jobs.

Oddly, however, Dr Joan Ballester of Barcelona Institute for Global Health reports in Nature Communications that “Recessions are generally associated with periods of faster life expectancy rise.” This claim is much disputed, but several studies back it up. Ballester tested death rates over the period 2000-2010 in 140 European regions, some of which rode out the economic crisis of 2008 easily, while others suffered badly.

Mortality rates fell across Europe during this period, in good times and bad, but Ballester found the biggest falls immediately after the crisis, when unemployment was skyrocketing and wages stagnating. Moreover, the worse a region was hit, the bigger its decline in death rates – an extra 1 percent a year in Spain, while in Germany the previously declining mortality rate stalled during the comparatively mild slowdown. The effect was strongest in winter.

Those who have reported similar outcomes in previous recessions have presented several theories to explain them and Ballester repeats these. “A one percentage point increase in unemployment is associated with a reduction in traffic mortality of 3 percent in the United States,” the paper notes as one easily tested example.

Recessions are also associated with reduced pollution. Since much of pollution's damage to health is long-term, it's unclear how much this contributes to an immediate drop in deaths, however. The same applies to the reduced tobacco and alcohol consumption recessions bring.

An alternative explanation is that people working reduced hours may use the spare time to get more exercise.

"Of course, recessions are not a desirable way to boost life expectancy" Ballester noted in a statement. In the long run, reduced economic activity is probably harmful. "What we need to ensure is that periods of economic expansion are also characterized by better air quality, fewer accidents and more healthy lifestyles,” he said.