Maps, pictures are data
Satellite photos provide a level of geographic specificity that national accounts do not. Another set of researchers used visual algorithms (related to those that recognize your face on Facebook or help navigate cars) to analyze these images pixel by pixel. Through this process, they could quantify poverty in each square kilometer of Uganda.
Satellite photos provide other useful information. In rural areas, we can see crops in the ground, allowing us to estimate harvest size -- even before the actual harvest. This data gives us a direct window into an essential part of the economic lives of many of the world's rural poor. The information can be used to build early warning systems for crop failure, to create crop insurance or target other forms of assistance.
There are many other important, unconventional sources of data. Consider cellphones. For most of the world's poor, each call and text has a very noticeable and real monetary cost.
-- SENDHIL MULLAINATHAN