By analyzing high-resolution satellite imagery of nighttime light intensity in a given area, researchers are able to estimate economic output at the local level. This measure is especially useful in remote, poor, and conflict-prone areas that lack reliable census, survey, and administrative data. However, since economic progress is often uneven, it’s not just the average level of nighttime light within a geographic region that matters. The geographical dispersion of nighttime light within a subnational locality also tells us something about how widely or narrowly the benefits of economic growth and development are being shared. As some geographic regions explode into luminescence, others stay dim or even recede into darkness—visual representations of economic stagnation and loss—and a growing body of research demonstrates this kind of spatial inequality can have far-reaching consequences. It can increase political polarization, slow economic development, provoke social unrest, and elevate the risk of violent conflict and terrorism.