Images of the earth at night may strike you as beautiful (if you're someone with a penchant for satellite photos) or distressing (if you're concerned about the effect of light pollution on migrating animals and/or you're a sea turtle). Some economists look at these photos and see tools for gathering data about other countries.
Previous research has found that luminosity--how much light a geographic area gives off at night--is a kind of shorthand for that area's economic productivity. Countries with a higher GDP (gross domestic product) have more stores that stay open at night, more cars on the road, and more electric lights guiding their citizens. More light means more business.
A new study by Yale economists Xi Chen and William Nordhaus asks just how useful this shorthand is. Can we use satellite photos to estimate the GDP of countries that don't collect or give out economic data? Haiti is ...
