Working Paper: CEPR ID: DP15050
Authors: Stephen J. Redding; Edward L. Glaeser; Caitlin Gorback
Abstract: How effective are restrictions on geographic mobility in limiting the spread of the COVID-19 pandemic? Using zip code data for Atlanta, Boston, Chicago, New York (NYC), and Philadelphia, we estimate that total COVID-19 cases per capita decrease on average by approximately 20 percent for every ten percentage point fall in mobility between February and May 2020. To address endogeneity concerns, we instrument for travel by the share of workers in remote work friendly occupations, and find a somewhat larger average decline of COVID-19 cases per capita of 27 percent. Using weekly data by zip code for NYC and a panel data specification including week and zip code fixed effects, we estimate a similar average decline of around 17 percent, which becomes larger when we measure mobility using NYC turnstile data rather than cellphone data. We find substantial heterogeneity across both space and over time, with stronger effects for NYC, Boston and Philadelphia than for Atlanta and Chicago, and the largest estimated coefficients for NYC in the early stages of the pandemic.
Keywords: COVID-19; mobility; cities
JEL Codes: H12; I12; J17; R41
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| COVID-19 prevalence (I14) | COVID-19 cases (Y10) |
| Higher initial infection rates (I12) | Stronger relationship between mobility and COVID-19 cases (J62) |
| Mobility varies over time and across cities (J62) | Impact of mobility on contagion varies (J62) |
| Mobility (J62) | COVID-19 cases (Y10) |
| 10 percentage point decrease in mobility (J62) | 17.27% decline in COVID-19 cases (Y10) |
| Mobility (J62) | COVID-19 prevalence (I14) |