By Immanual John Milton

The sudden shutdown of schools and businesses in US cities during the Covid-19 pandemic had a host of dramatic consequences for residents as commuting and socialization patterns were upended. Those measures have had a lingering side effect, according to a new study from researchers at Massachusetts Institute of Technology: People are now less likely to visit parts of their home cities that are economically different.

Looking at mobile phone data from more than 1 million people in Boston, Seattle, Los Angeles and Dallas, the study’s authors tracked users from January 2019 to December 2021 to see how people in different socioeconomic classes changed where they went during the pandemic. The results showed how the diversity of urban encounters drastically declined in early 2020, as travel restrictions and other public health measures to slow the spread of the virus swept cities. But while overall mobility levels and time spent outside the home recovered as schools and businesses reopened, the researchers found that the travel habits of residents had shifted: As of late 2021, people remained less likely to engage in social exploration, which the study authors define as the likelihood of visiting a new place where they earn significantly more or less than than the general population. Instead, they just returned to familiar destinations.