GDP Linked to How Bright a Country Looks at Night

When former Grand National Party chairwoman Park Geun-hye visited Washington in March 2005, then U.S. defense secretary Donald Rumsfeld showed her a satellite photo of the Korean Peninsula at night that showed a brightly-lit South Korea and pitch-dark North. Rumsfeld said that he looked at the photo when he thought about Korea, which vividly showed the huge gap between the systems that divide the two Koreas.

Economists echo Rumsfeld's words. In a paper published in the Proceedings of the National Academy of Sciences, a research team led by William Nordhaus of Yale University claims a nation's GDP can be estimated fairly accurately based on the radiance measured using nighttime satellite images.

The team overlaid a grid on nighttime satellite photos of the world taken by the U.S. Air Force in 1992-2008 and built a statistical model to analyze changes in radiance. The model enabled them to gauge the GDP for countries with unclear economic statistics such as Iraq, Algeria and Haiti.

Earlier in 2009, a research team at Brown University published a paper saying that a nation's GDP trend was in line with changes in light density at night as shown in photos taken from outer space by the National Oceanic and Atmospheric Administration. According to the NOAA, North Korea's "night lights" are at mere 2 percent of the South's.