Schools under Mandatory Testing Can Mitigate the Spread of SARS-CoV-2
Joint with Ingo Isphording, Reyn van Ewijk and Nico Pestel
2022, PNAS
Winner of the best paper award of the Deutsche Gesellschaft für Gesundheitsökonomie
For a German summary see IZA Standpunkt 101; Media coverage in Welt and Focus.
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. A central anti-pandemic measure in German schools included mandatory rapid testing multiple times per week. Our results are consistent with mandatory testing contributing to the containment of the viral spread. We find a short-term increase in infection rates right after summer breaks, indicating the uncovering of otherwise undetected (asymptomatic) cases through the testing. After a period of about two weeks after school re-openings, the growth of case numbers is smaller in states which re-opened schools compared to the control group of states still in summer break. The results show a similar pattern for older age groups as well, arguably as a result of detected clusters through the school testing. This means that under certain conditions open schools can play a role in containing the spread of the virus. Our results suggest that closing schools as a means to reduce infections may have unintended consequences by giving up surveillance and should be considered only as a last resort.
Is large-scale rapid CoV-2 testing a substitute for lockdowns?
Joint with René Glawion, Peter G. Kremsner, Timo Mitze, Gernot J. Müller, Dominik Papies, Felix Schulz and Klaus Wälde
2022, PLOS ONE
Various forms of contact restrictions have been adopted in response to the Covid-19 pandemic. Around February 2021, rapid testing appeared as a new policy instrument. Some claim it may serve as a substitute for contact restrictions. We study the strength of this argument by evaluating the effects of a unique policy experiment: In March and April 2021, the city of Tübingen set up a testing scheme while relaxing contact restrictions. We compare case rates in Tübingen county to an appropriately identified control unit. We employ the synthetic control method. We base interpretations of our findings on an extended SEIR model. The experiment led to an increase in the reported case rate. This increase is robust across alternative statistical specifications. This is also due to more testing leading initially to more reported cases. An epidemiological model that corrects for ‘more cases due to more testing’ and ‘reduced testing and reporting during the Easter holiday’ confirms that the overall effect of the experiment led to more infections. The number of rapid tests were not sufficiently high in this experiment to compensate for more contacts and thereby infections caused by relaxing contact restrictions.
Dissertation Paths: Advisors and Students in the Economics Research Production Function
Joint with Joshua Angrist
Elite economics PhD programs aim to train graduate students for a lifetime of academic research. This paper asks how advising affects graduate students’ post-PhD research productivity. Advising is highly concentrated: at the eight highly-selective schools in our study, a minority of advisors do most of the advising work. We quantify advisor characteristics such as an advisor’s own research output and aspects of the advising relationship like coauthoring and research field affinity that might contribute to student research success. Students advised by research-active, prolific advisors tend to publish more, while coauthoring has no effect. Student-advisor research affinity also predicts student success. But a school-level aggregate production function provides much weaker evidence of causal effects, suggesting that successful advisors attract students likely to succeed–without necessarily boosting their students’ chances of success. Evidence for causal effects is strongest for a measure of advisors’ own research output. Aggregate student research output appears to scale linearly with graduate student enrollment, with no evidence of negative class-size effects. An analysis of gender differences in research output shows male and female graduate students to be equally productive in the first few years post-PhD, but female productivity peaks sooner than male productivity.
The Effect of an Editorial Connection in the Peer Review Process of Economic Journals
This study investigates whether economic scholars with a connection to an editor have an advantage. I use panel data and variation in the timing of editorial appointments to estimate connection effects. The findings suggest that editorial connections boost productivity by 15% during the years of the connected editor’s appointment. These effects are likely due to editorial knowledge spillovers as I document productivity increases also in other similar journals. This study is essential to better understand the integrity and fairness of the publication process by examining the potential biases introduced by editorial connections.
Interdisciplinary Research in Economics
Joint with Tristan Stahl
Interdisciplinarity is seen as a desirable aspect of research projects that is often promoted by research institutions. However, our study reveals that interdisciplinary research projects are associated with lower citation counts and worse journal placements. These findings show that there is a misalignment between the goals of research institutions and researchers, because researchers need highly ranked publications for their promotions. We study a sample of over 13,000 research articles published in economics journals in 2011 and 2012 and present three novel measures of interdisciplinarity. We conduct a Specification Curve (SC) Analysis, which allows for a transparent discussion of data analytic decisions and the visualization of their impact on effect sizes. Furthermore, we find that conducting interdisciplinary research is not a high-risk, high-reward endeavor but instead: that citation counts to interdisciplinary articles do not catch up with those of non-interdisciplinary articles over time. Our results are not due to a false classification of cross disciplinary articles as having low interdisciplinarity, as shown by a robustness exercise where we include business articles and we show that effect sizes are more emphasized for high-ability researchers. The results of this study may be used to better align researcher and institutional goals.