Mobile phone data is a valuable tool for monitoring food security in low-income countries.

A 2012 demographic study of food consumption patterns among 7,500 households “a Central African country” (name not disclosed) produced intriguing results. The survey was by no means easy. One dataset tracked food consumption and another kept track of all phone calls (caller, time, location) along with airtime credit purchases. The two sets were then compared to see how airtime expenses matched up with consumption or high-value foods (sugar) or low-value foods (sorghum).

What did researchers find?

• Airtime purchases are significantly correlated with the consumption of high-value food items
• There was little correlation between airtime purchases and broadly cultivated items such as cassava and beans
• There was negative correlation between airtime expenses and the consumption of white sweet potato, which is a very cheap and broadly cultivated item
• New hypothesis: expenditure in mobile phone top up is proportional to the expenditure in food in the markets