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We use event-study models based on staggered summer vacations in Germany to estimate the effect of school re-openings after the summer of 2021 on the spread of SARS-CoV-2. Estimations are based on daily counts of confirmed coronavirus infections across all 401 German counties. Our results are consistent with mandatory testing contributing to containment of cases by uncovering otherwise undetected (asymptomatic) cases. Case numbers in school-aged children spike in the first week after the summer breaks but then turn not significantly different from zero. Case numbers in prime-aged age groups gradually decrease after school re-openings, arguably as a result of detected clusters through the school testing. The age group 60+ remains unaffected by the school re-openings. We conclude that the combination of mandatory testing and compulsory school attendance can provide an unbiased and near-complete surveillance of the pandemic. Thus, under certain conditions open schools can play a role in containing the spread of the virus. The trade-off between reducing contacts and losing an important monitoring device has to be taken seriously when re-considering school closures as a nonpharmaceutical intervention under the current circumstances.

This paper studies job search behavior in the midst of a pandemic recession. We use long-running panel data from the Netherlands (LISS) and complement the core survey with our own COVID-specific module, conducted in June 2020, surveying job search effort of employed as well as unemployed respondents. We estimate an empirical model of job search over the business cycle over the period 2008-2019 to explore the gap between predicted and actual job search behavior in 2020. We find that job search during the pandemic recession differs strongly from previous downturns. The unemployed search significantly less than what we would normally observe during a recession of this size, while the employed search mildly more. Expectations about the duration of the pandemic seem to play a key role in explaining job search effort for the unemployed in 2020. Furthermore, employed subjects affected by changes in employment status due to COVID-19 are more likely to search for a job. Conversely, beliefs about infection risk do not seem to be related to job search in a systematic way.

Schulen tragen nicht zu den im Moment steigenden Corona-Fallzahlen bei. Das Wiederöffnen der Schulen nach den deutschen Sommerferien trug vermutlich sogar dazu bei, dass die Inzidenzzahlen niedriger geblieben sind, als sie bei geschlossenen Schulen gewesen wären. Die obligatorischen Schnelltests in Schulen stellen ein wichtiges Mittel dar, Ausbrüche frühzeitig zu erkennen und zu isolieren, was zur Eindämmung der Pandemie beitragen kann.

This paper studies the effect of the end of school summer breaks on SARS-CoV-2 cases in Germany. We exploit variation in the staggered timing of summer breaks across federal states which allows us to implement an event study design. We base our analysis on official daily counts of confirmed coronavirus infections by age groups across all 401 German counties. We consider an event window of two weeks before and three weeks after the end of summer breaks. Over a large number of specifications, sub-group analyses and robustness checks, we do not find any evidence of a positive effect of school re-openings on case numbers. On the contrary, our preferred specification indicates that the end of summer breaks had a negative effect on the number of new confirmed cases. Three weeks after the end of summer breaks, cases have decreased by 0.55 cases per 100,000 inhabitants or 27 percent of a standard deviation. Our results are not explained by changes in mobility patterns around school re-openings arising from travel returnees. We conclude that school re-openings in Germany under strict hygiene measures combined with quarantine and containment measures have not increased the number of newly confirmed SARS-CoV-2 infections.

We study the impact of short-term exposure to ambient air pollution on the spread and severity of Covid-19 in Germany. We combine data on county-by-day level on confirmed cases and deaths with information on local air quality and weather conditions and exploit short-term variation in the concentration of particulate matter (PM10) and ozone (O3). We apply fixed effects regressions controlling for global time-varying confounding factors and regional time-invariant confounding factors on the county level, as well as potentially confounding weather conditions and the regional stage of the pandemic. We find significant positive effects of PM10 concentration after the onset of the illness on Covid-19 deaths specifically for elderly patients (80+ years): higher levels of air pollution by one standard deviation 3 to 12 days after developing symptoms increase deaths by 30 percent (males) and 35 percent (females) of the mean. In addition, air pollution raises the number of confirmed cases of Covid-19. The timing of results supports mechanisms of air pollution affecting the severity of already realized infections. Air pollution appears not to affect the probability of infection itself.