  We assess the impact of COVID-19 response measures implemented in Germany and
Switzerland on cumulative COVID-19-related hospitalization and death rates. Our
analysis exploits the fact that the epidemic was more advanced in some regions
than in others when certain lockdown measures came into force, based on
measuring health outcomes relative to the region-specific start of the epidemic
and comparing outcomes across regions with earlier and later start dates. When
estimating the effect of the relative timing of measures, we control for
regional characteristics and initial epidemic trends by linear regression
(Germany and Switzerland), doubly robust estimation (Germany), or synthetic
controls (Switzerland). We find for both countries that a relatively later
exposure to the measures entails higher cumulative hospitalization and death
rates on region-specific days after the outbreak of the epidemic, suggesting
that an earlier imposition of measures is more effective than a later one. For
Germany, we also evaluate curfews (as introduced in a subset of states) based
on cross-regional variation. We do not find any effects of curfews on top of
the federally imposed contact restriction that banned groups of more than 2
individuals. Finally, an analysis of mobility patterns in Switzerland shows an
immediate behavioral effect of the lockdown in terms of reduced mobility.
