Perpetual Motion: High-Frequency Human Mobility in Three African Countries

This paper explores the within-country movements of people in three African countries. Although previous studies in other low-income settings have examined patterns of seasonal migration and daily commuting, much less is known about mobility at other temporal frequencies. This paper draws on a novel source of data from smartphone locations. These data allow us to observe the movements of a large set of individuals over a one-year period. We can characterize with considerable detail the locations that people visit and the frequency with which they make trips. The average smartphone user in our data ventures more than 10 km from home on 12-15% of the days when they are observed. On average, when we observe them away from home, our users are typically 35-50 km from home. We can characterize many of the specific locations that people visit when they are away from home. These include locations associated with shops and markets, government offices, and places offering a range of goods, services, and recreational venues. Big cities seem to be particularly important destinations, perhaps reflecting the range of amenities that they offer to visitors. We develop a conceptual framework that characterizes the role of visits for individuals and provides a number of testable predictions that are consistent with the movement patterns that we observe in the data. Although our sample of smartphone users is not representative of national populations, their mobility patterns offer useful insights into spatial frictions and the geographic patterns of economic activity.