About us

The Billion Prices Project is an academic initiative that uses prices collected from hundreds of online retailers around the world on a daily basis to conduct economic research. This page shows our most recent research leveraging high-frequency price data, as well as the US daily inflation index (updated monthly on this page).

Geographic Coverage

BPP Geographic Coverage
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Our Work

Argentina CPI

InflacionVerdadera.com was created in 2007 to provide alternative price indexes to the official ones in Argentina. From 2007 to 2012 we published a Food and Drinks Index as well as a Basic Food Basket Index, using a combination of daily prices from two large supermarkets in Buenos Aires and the same methodologies of the INDEC before its intervention in 2007. Our task led us to create The Billion Prices Project at the Massachusetts Institute of Technology (MIT), and then PriceStats, the first private enterprise to calculate aggregate price indexes in the world.

US Daily Index

This series are published by PriceStats and shared here for educational purposes with a significant lag. For methodology and other details please visit www.pricestats.com

Offline Data Collection

We periodically conduct simultaneous online and offline (in-store) data collection efforts in retailers around the world. This allow us to:
– Validate online data as a representative source of high-frequency price information (since most of the transactions take place offline for now, even in developed countries)
– Better understand how offline pricing behaviors are being affected by the web and mobile browsing/price‐checking technologies.

Our Research Papers

“Are Online and Offline Prices Similar? Evidence from Large Multi-Channel Retailers“, Alberto Cavallo (2016). American Economic Review – January 2017, Vol. 107, No. 1, (pp. 283-303)

I present the results of the first large-scale comparison of online and offline prices simultaneously collected from the websites and physical stores of 56 large multi-channel retailers in 10 countries. I find that price levels are identical about 72% of the time for the products sold in both locations, that there is no evidence of prices varying with the location of the ip address or persistent browsing habit, and that price changes are un-synchronized but have similar frequencies and average sizes.

“Inflation Expectations, Learning, and Supermarket Prices: Evidence from Field Experiments”, Alberto Cavallo, Guillermo Cruces, and Ricardo Perez-Truglia (2016). American Economic Journal: Macroeconomics – Forthcoming

Using field experiments with about 10,000 subjects across United States and Argentina, we find that both models of rational inattention and learning from personal experience are relevant in the formation of inflation expectations. Individuals learn from (readily available) inflation statistics, but also assign weight to their own memories of price changes.

“The Billion Prices Project: Using Online Prices for Measurement and Research“, Alberto Cavallo and Roberto Rigobon (2016). Journal of Economic Perspectives – Spring 2016, Vol 30(2): 151-78.

We describe our work with online data at the Billion Prices Project at MIT and discuss key lessons for both inflation measurement and some fundamental research questions in macro and international economics. We show how online prices can be used to construct daily price indexes in multiple countries and to avoid measurement biases that distort evidence of price stickiness and international relative prices.

See all our Research Papers

Argentina Daily CPI


US Daily CPI

Screenshot 2016-07-15 10.58.18

Daily Inflation Data

If you are looking for more high-frequency inflation data across countries and sectors, please contact PriceStats, the company that collects the online data we use in our research initiatives and experimental indexes.

The Data

Online – Offline Price Comparison

Description: Online and offline prices for individual goods sold by 56 large multi-channel retailers in 10 countries: Argentina, Australia, Brazil, Canada, China, Germany, Japan, South Africa, UK, and the US.

  • Countries: 10
  • Dates : 2014 to 2016

Supermarket Data

Description: Daily prices for all goods sold by 7 of the largest SUPERMARKETS in Latin America and the US: 2 in Argentina, 1 in Brazil, 1 in Chile, 1 in Colombia, 1 in Venezuela, and 1 in the US.

  • Frequency: Daily
  • Countries: 6
  • Dates : 2007 to 2011
See all our data
Online Prices Per Day
Retailers - More than
BPP on the Press

Latest News

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Meet Our Team

Roberto Rigobon
Founder & Project Leader
Alberto Cavallo
Founder & Project Leader
Diego Aparicio
Diego Aparicio
Research Assistant
Maria Fazzolari
Research Assistant

Video Presentation

Financial and Research Support

We thank all the current and past MIT students that participated in the project through MIT’s UROP program for their help and enthusiasm.
For our technology and computational needs, we receive outstanding help from Mark Riedesel, Chay Casso, Armand Doucette, Ray Faith, Ken Valentine, and others at Sloan Technology Services. We also thank the members of SIPB at MIT for hosting this page.