When do shelter‐in‐place orders fight COVID‐19 best? Policy heterogeneity across states and adoption time

Abstract

This study explores the impact of Shelter-in-Place Orders (SIPOs) on health, with attention to heterogeneity in their impacts. First, using daily state-level social distancing data, we document that adoption of a SIPO was associated with a 9%–10% increase in the rate at which state residents remained in their homes full-time. Using daily state-level coronavirus case data, we find that approximately 3 weeks following the adoption of a SIPO, cumulative COVID-19 cases fell by approximately 53.5%. However, this average effect masks important heterogeneity across states-early adopters and high population density states appear to reap larger benefits from their SIPOs.