As the world's population grows, censuses are increasingly more difficult to take. But technology continues to advance at an accelerated rate, which means scientists could potentially find new and innovative ways to take a census more efficiently. A new study suggests that the fast-growing cell phone industry could potentially help solve the problem.
According to Science Mag, scientists have found a way to map large populations using cell phone records. This cell phone approach would not only work to count the population but also track where they live and where they go everyday. An exhaustive record of nearly everyone's location and day-to-day activities could provide incredible insight into the condition of a given population or society. Admittedly, the idea is slightly frightening, considering a government could potentially use the cell phone census method to track and spy on its citizens.
The method works thanks to the incredible prevalence of cell phones and cell phone technology in developed nations. Ninety-six percent of the entire world's population have cell phone plans, including in developing nations. In fact, in many developing nations the total number of cell phone plans have surpassed the total population since many people have more than one phone.
Scientists can utilize this widespread cell phone use to pinpoint cell phone tower activity, calculating the cell phone use to estimate local population density -- even in nations where a census is not taken or strongly regulated.
"This is the first time people have provided statistical evidence that population data produced from cellphone records are of really good quality," said Renaud Lambiotte, an applied mathematician at the University of Namur in Belgium. Lambiotte was not involved in the study.
The study was led by geographer Catherine Linard of the Université Libre de Bruxelles and Pierre Deville, a data scientist from the Université Catholique de Louvain in Belgium. The scientists used WorldPop, a piece of open-source software, and cell phone data to make a detailed population density map of France and Portugal. Linard and Deville obtained cell phone call records from all the major service providers in the country, analyzing more than one billion calls.
The study amassed the cell phone records from 2 million users in Portugal and 17 million in France. The information used included the originating and receiving phone towers, the cell phone call's time and its user. Accounting for variables, the team managed to create an accurate model of population density, essentially replacing the census.
To read the official study, click here.
For more on science and cell phones, check out the story of a West Virginia town that banned cell phones for the sake of science.