Health Policy$ense

Wuhan Lockdown Halted Spread of Coronavirus Across China

New Econometric Study Quantifies Impact Over Five Weeks

As increasing numbers of people domestically and abroad face mandatory “lockdowns,” we have new evidence that these severe restrictions on movement are effective in containing the spread of the novel coronavirus. In a just-released working paper, LDI Senior Fellow Hanming Fang, PhD and colleagues Long Wang, PhD, of ShanghaiTech University, and Yang (Zoe) Yang, PhD, of Chinese University of Hong Kong, quantify the effects of the lockdown of the city of Wuhan on January 23, 2020, showing that it played a crucial role in reducing cases of COVID-19 in other Chinese cities and halting the spread of the virus.

Without the Wuhan lockdown, the researchers estimate that between January 23, 2020 and February 29, 2020, COVID-19 cases would have been 65% higher in the 347 Chinese cities outside Hubei province, and 53% higher in the 16 non-Wuhan cities inside Hubei, even with the social distancing measures implemented by other cities. In their “counterfactual” simulations (that is, with no Wuhan lockdown), cities outside Hubei province would have had 20,810 cases, compared to the 12,626 they actually recorded; cities inside Hubei (other than Wuhan) would have had 23,400 cases, compared to 15,330 actual cases. This striking impact is shown, daily and cumulatively, in the Figure below: