Open AccessAssessing alternative indicators for Covid-19 policy evaluation, with a counterfactual for Sweden
Author(s) -
Giancarlo Spagnolo,
Chiara Latour,
Franco Peracchi
Publication year - 2022
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0264769
Subject(s) - counterfactual thinking , covid-19 , counterfactual conditional , construct (python library) , econometrics , false positive paradox , statistics , medicine , computer science , economics , mathematics , psychology , virology , social psychology , disease , pathology , outbreak , infectious disease (medical specialty) , programming language
Using the synthetic control method, we construct counterfactuals for what would have happened if Sweden had imposed a lockdown during the first wave of the COVID-19 epidemic. We consider eight different indicators, including a novel one that we construct by adjusting recorded daily COVID-19 deaths to account for weakly excess mortality. Correcting for data problems and re-optimizing the synthetic control for each indicator, we find that a lockdown would have had sizable effects within one week. The much longer delay estimated by two previous studies focusing on the number of positives cases is mainly driven by the extremely low testing frequency that prevailed in Sweden in the first months of the epidemic. This result appears relevant for choosing the timing of future lockdowns and highlights the importance of looking at several indicators to derive robust conclusions. We also find that our novel indicator is effective in correcting errors in the COVID-19 deaths series and that the quantitative effects of the lockdown are stronger than previously estimated.