Luminosity analysis is the study of satellite images taken of the earth at night. The basic premise is that lights can serve as a proxy for Gross Domestic Product (GDP), as most modern economic activity involves lights visible from space. Analysis typically focuses on light density – the value of luminosity divided by geographic area.

A 2012 paperfrom J. Vernon Henderson, Adam Storeygard, and Robert Weil finds that the elasticity of GDP to lights is 0.28 – that is, a 100 percent increase in a country’s average light density is associated with a 28 percent increase in GDP. However,