Lockdowns & Rebounds: A Data Analysis of What Happens Next

We present an analysis of COVID-19 lockdowns for 56 countries based on daily mobility levels and estimated virus transmission rates. What will happen to transmission rates when countries begin to ease restrictions and mobility levels start to increase? Our analysis, based on data up to May 11th, 2020, show how, even when mobility levels increase, most countries (87%) continue to reduce the effective reproduction number (Rt) of the virus. Moreover, when restrictions were eased only after Rt was below 1, then countries always managed to maintain Rt≤ 1 even as mobility levels rose, at least for the period covered by the data. In contrast, when restrictions were eased before Rt fell below 1, then only 55% of countries managed to subsequently reduce Rt to below 1. By easing restrictions cautiously and carefully, it was possible to avoid a rebound in transmission rates while allowing mobility levels to increase. © 2020 ACM.