A new study finds that mobile phone data can be used for human population mapping in situations such as disasters, conflicts and epidemics due to its high level of penetration around the globe. Researchers called the proliferation of cellphones “an unprecedented solution” to the lack of timely information about people’s movements during crises.
The use of mobile phone data for epidemiological research has been increasing. The Economist recently called for call data records (CDRs) from west Africa to be released to researchers to provide them with some data to analyze in order to better inform the fight against Ebola. Even though cell phone penetration is relatively low in remote rural areas, the publication argued, “CDRs are nevertheless better than simulations based on stale, unreliable statistics. If researchers could track population flows from an area where an outbreak had occurred, they could see where it would be likeliest to break out next—and therefore where they should deploy their limited resources.”
An effort to use CDRs in the fight against Ebola has been stymied, The Economist reported, despite negotiations between researchers, local operators and the GSMA.
The new research, published in the “Proceedings of the National Academy of Sciences of the United States of America,” confirms that call data can be useful in population mapping and tracking over time. It relied on more than 1 billion mobile phone records from Portugal and France and was performed by researchers from Belgium, the U.S., France and Sweden.
Population mapping is constrained by the limitations of censuses and surveys, according to the paper’s abstract, so detailed changes across relatively small timeframes such as days, weeks, months or even from one year to the next are nearly impossible to come by — and it’s particularly difficult in low-income countries.
“Knowing where people are is critical for accurate impact assessments and intervention planning, particularly those focused on population health, food security, climate change, conflicts, and natural disasters,” the authors wrote.
Mobile phone penetration is more than 100% in many developing countries, they noted, but also reaches as high as 90% in undeveloped regions and is constantly rising. Analyzing call records, the researchers were able to estimate population densities on a national scale and over different timeframes, and added that they were able to sufficiently anonymize the data to protect individual privacy.
“With similar data being collected every day by [mobile phone] network providers across the world, the prospect of being able to map contemporary and changing human population distributions over relatively short intervals exists, paving the way for new applications and a near real-time understanding of patterns and processes in human geography,” the authors concluded.
