Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

How Mobile Phone Data Reveals Food Consumption Patterns in Central Africa

Food shortages in developing countries have always been difficult to monitor in real time. But mobile phone data is changing that, say demographers.

  • December 17, 2014

An increasingly important side-effect of the mobile phone revolution is that the big data it generates has become a high-resolution microscope for examining the nature of society. Various teams have shown how mobile phone data reveals patterns of commuting, criminal activity and even human reproductive strategies.

Now Adeline Decuyper at the Université catholique de Louvain in Belgium, and a few pals, say they have used mobile phone usage patterns in a Central African country to determine food consumption patterns. They say the work suggests that mobile phone data could be a valuable tool for monitoring food security in low and middle-income countries.

Decuyper and co began with two datasets. The first is a ground truth survey of food consumption among 7500 households in a Central African country throughout 2012, carried out by the World Food Programme. (The team do not say which country they have studied but a cursory study of the data suggests that it is Rwanda.)

The survey contains 486 questions about the demographics of the household members, the characteristics of the home shelter and household income as well as many specific questions related to food consumption, such as the number of times each type of food was consumed in the last seven days, difficulties in accessing food throughout the year and so on.

The second dataset is a record of all calls for a significant portion of the population from one large mobile phone carrier. Each record includes the caller and callee ID, the cell tower initiating the call and the date and time. The dataset also includes the history of airtime credit purchases from the same population of users.

The hypothesis that Decuyper and co investigate is that the pattern of airtime credit purchases reflects the pattern of food consumption and so can therefore be used as a proxy for this in future.

To find out, they divide the population into geographical areas of between 10,000 and 50,000 inhabitants. They then assign a home location to each mobile phone user in this area based on the place where they make the most calls. For each user, they also plotted their airtime credit purchase behaviour, showing how much they bought and how often.

Finally, they compared the sum of airtime expenses of each individual with various food consumption variables. For example, they compared airtime expenses with how often people ate high-value foods such as sugar and sweets or low value foods such as cassava or sorghum.

The results make for interesting reading. Decuyper and co found that airtime purchases are significantly correlated with the consumption of high-value food items such as vitamin rich vegetables, rice, bread, sugar and fresh meat.

They also found that there was little correlation between airtime purchases and broadly cultivated items such as cassava and beans.

That’s interesting because the high-value items generally have to be bought in the market whereas the low value items tend to be grown at home. “Therefore this study is compatible with a new hypothesis: expenditure in mobile phone top up is proportional to the expenditure in food in the markets,” conclude Decuyper and co.

That hypothesis is backed up by the discovery of a negative correlation between airtime expenses and the consumption of white sweet potato, which is a very cheap and broadly cultivated item. “This suggests that when people can afford to, they will reduce their consumption of sweet potato,” say the team.

The results suggest that mobile phone data could become a hugely important tool for the real-time monitoring of food consumption patterns. The idea is that this kind of data could warn of food shortages and potential national crises, as they occur.

That’s a hugely important function, particularly in parts of the world where surveys are time-consuming, costly and sometimes impossible to carry out. Useful stuff!

Ref: arxiv.org/abs/1412.2595 : Estimating Food Consumption and Poverty indices with Mobile Phone Data

The latest Insider Conversation is live! Listen to the story behind the story.

Subscribe today
Already a Premium subscriber? Log in.

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

Want more award-winning journalism? Subscribe and become an Insider.
  • Insider Premium {! insider.prices.premium !}*

    {! insider.display.menuOptionsLabel !}

    Our award winning magazine, unlimited access to our story archive, special discounts to MIT Technology Review Events, and exclusive content.

    See details+

    What's Included

    Bimonthly magazine delivery and unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

    Access to the magazine PDF archive—thousands of articles going back to 1899 at your fingertips

    Special discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

    First Look: exclusive early access to important stories, before they’re available to anyone else

    Insider Conversations: listen in on in-depth calls between our editors and today’s thought leaders

  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly magazine delivery and unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

    Access to the magazine PDF archive—thousands of articles going back to 1899 at your fingertips

    Special discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning magazine and daily delivery of The Download, our newsletter of what’s important in technology and innovation.

    See details+

    What's Included

    Bimonthly magazine delivery and unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.