Can our parents collect reliable and timely price data?

During the past few years, interest in high-frequency price data has grown steadily.  Recent major economic events - including the food crisis and the energy price surge – have increased the need for timely high-frequency data, openly available to all users.  Standard survey methods lag behind in meeting this demand, due to the high cost of collecting detailed sub-national data, the time delay usually associated with publishing the results, and the limitations to publishing detailed data. For example, although national consumer price indices (CPIs) are published on a monthly basis in most countries, national statistical offices do not release the underlying price data.

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This led us to search for alternative ways to collect and present price data. We realized one important fact: our parents, neighbors, friends and the rest of the crowd can collect price data! However, would this price data be reliable and timely? We set out to examine the feasibility of this approach.

Our innovative pilot study of crowd-sourced price data collection through mobile phones has combined the need for high-frequency data, recent developments in the ICT sector, and the power of the crowd. Unlike the CPIs, which employ professional price collectors to collect price data, our method involves employing “non-professional” price collectors using their mobile phones as a way to collect the prices of food items in eight pilot countries - Brazil, Bangladesh, India, Indonesia, Kenya, Nigeria, Pakistan and the Philippines. Prices were collected for 30 basic commodities - such as rice, meat, vegetables, and sugar - from around 2,500 supermarkets in 270 survey locations, by a crowd of 7,000 non-professionals.

A private company - JANA (www.jana.com) - helped conduct the pilot study, recruit non-professional price collectors, and collect the data. Data were verified and validated, and those providing price data were rewarded with phone airtime credits though the backend billing systems of mobile operator partners.

What did we learn? The results from the pilot tell us that, yes, the crowd can collect reliable and timely prices – but you need to provide incentives and implement good verification and validation processes. The resulting data are comparable over time and space, and timeliness is pretty good – the time lag is only about a month. And, importantly, the resulting data are open to all users.

We’ve been analyzing the data for a few weeks now, and put together an interactive dashboard to help you explore the dataset on your own. Or, if you prefer, download the entire dataset at data.worldbank.org/data-catalog/crowd-sourced-price-collection and use your own tools. Let us know what you find, and whether you would deem it useful if we went beyond the pilot.