That cities have great inequalities is hardly news, with many divided along ethnic or racial lines. Indeed, Harvard’s Thomas Schelling famously modeled urban segregation way back in 1969.
Research from Stanford utilizes mobile phone data to help us understand how our segregated cities can translate into our daily lives, and especially what happens when we leave home to study, work, shop, or relax.
Daily lives
While census data provides a good idea of residential segregation, it tends to be a static representation, so the researchers wanted to use mobile data to better understand how people move around. The researchers gathered geolocation data from around 18 million mobile phones to explore how Americans experience racial segregation in their daily activities.
They analyzed over 360 urban areas and found that people tend to be exposed to a far more diverse range of people when they step outside of their immediate neighborhood, which therefore lowers the level of segregation they experience. The aim was to understand how people experienced isolation as they moved around the city.
The first step was to understand where each person lived so that they could then identify when they stepped outside of their home. They then looked at the demographics of each phone owner so they could chart the segregation.
Diverse interactions
The results show that most cities facilitated diverse interactions, with around 88% of people experiencing less segregation in their day-to-day lives than their residential experience would suggest. This was especially so in the commercial areas of the city, such as where people eat, shop, or enjoy entertainment, which were generally not segregated at all.
Areas such as schools and churches, however, were far less integrated, which the researchers expected because religious affiliation is often broken down by race, while schools tend to mimic residential segregation patterns.
The data also found that isolation tended to be higher in the mornings and evenings, when most people were at home, than during the day.
“Lunchtime turns out to be a time of day when people mix more,” the researchers explain. “People are coming in from the suburbs to work, and then everybody’s walking around together, going to lunch together in the middle of the city. That’s a time of day that exposes people to others.”
Indeed, the experienced isolation was universally lower than residential isolation, and especially so in cities with higher population density and with greater use of public transport. It was also true in areas with higher levels of income, education, and social mobility.
Consistent links
While there were gaps in the levels of segregation found in cities, the research nonetheless found a consistent link between lived and residential segregation.
“If you rank cities based on residential segregation and you rank cities based on experienced segregation, it’s sort of the same ranking,” the researchers say. “It’s very correlated.”
The precise nature of the link between lived and residential segregation isn’t entirely clear, however, but the researchers believe that policies that specifically aim to facilitate access to leisure and commercial spaces would significantly address the many harmful effects of segregation.
“One thing we can try to do is think about how to change where people live,” they conclude. “It takes a long time for that kind of change to happen. This paper points out that people’s actual experiences depend on lots of other things that potentially could change a lot more quickly.”
