Human mobility restrictions and the spread of the Novel Coronavirus (2019-nCoV) in China

We quantify the causal impact of human mobility restrictions, particularly the lockdown ofWuhan on January 23, 2020, on the containment and delay of the spread of the Novel Coronavirus (2019-nCoV). Weemploy differencein-differences (DID) estimations to disentangle the lockdown effect on human mobility reductions from other confounding effects including panic effect, virus effect, and the Spring Festival effect. The lockdown ofWuhan reduced inflows toWuhan by 76.98%, outflows fromWuhan by 56.31%, and within-Wuhan movements by 55.91%. We also estimate the dynamic effects of up to 22 lagged population inflows fromWuhan and other Hubei cities the epicenter of the 2019-nCoV outbreak - on the destination cities' new infection cases. We also provide evidence that the enhanced social distancing policies in the 98 Chinese cities outside Hubei province were effective in reducing the impact of the population inflows from the epicenter cities in Hubei province on the spread of 2019-nCoV in the destination cities. We find that in the counterfactual world in whichWuhan were not locked down on January 23, 2020, the COVID-19 cases would be 105.27% higher in the 347 Chinese cities outside Hubei province. Our findings are relevant in the global efforts in pandemic containment. (c) 2020 Elsevier B.V. All rights reserved.