MIT Billion Prices project

The Billion Prices Project (BPP) was an academic initiative at MIT Sloan and Harvard Business School that used prices collected from hundreds of online retailers around the world daily to conduct research in macro and international economics and compute real-time inflation metrics. It was started in 2008 by professors Alberto Cavallo and Roberto Rigobon.

Source: Wikipedia — MIT Billion Prices project (CC BY-SA 4.0)