Correcting the reproduction number for time-varying tests: A proposal and an application to COVID-19 in FranceJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Matteo L. Pintus, Patrick A. Pintus and Miriam Teschl, PLOS ONE, Volume 18, Issue 2, pp. e0281943, 2023

We provide a novel way to correct the effective reproduction number for the time-varying amount of tests, using the acceleration index (Baunez et al., 2021) as a simple measure of viral spread dynamics. Not correcting results in the reproduction number being a biased estimate of viral acceleration and we provide a formal decomposition of the resulting bias, involving the useful notions of test and infectivity intensities. When applied to French data for the COVID-19 pandemic (May 13, 2020—October 26, 2022), our decomposition shows that the reproduction number, when considered alone, characteristically underestimates the resurgence of the pandemic, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all relevant information and captures in real time the sizable time variation featured by viral circulation, it is a more parsimonious indicator to track the dynamics of an infectious disease outbreak in real time, compared to the equivalent alternative which would combine the reproduction number with the test and infectivity intensities.

Mental disorders, COVID-19-related life-saving measures and mortality in France: A nationwide cohort studyJournal articleMichael Schwarzinger, Stéphane Luchini, Miriam Teschl, François Alla, Vincent Mallet and Jürgen Rehm, PLOS Medicine, Volume 20, Issue 2, pp. e1004134, 2023

Meta-analyses have shown that preexisting mental disorders may increase serious Coronavirus Disease 2019 (COVID-19) outcomes, especially mortality. However, most studies were conducted during the first months of the pandemic, were inconclusive for several categories of mental disorders, and not fully controlled for potential confounders. Our study objectives were to assess independent associations between various categories of mental disorders and COVID-19-related mortality in a nationwide sample of COVID-19 inpatients discharged over 18 months and the potential role of salvage therapy triage to explain these associations.
Methods and findings:
We analysed a nationwide retrospective cohort of all adult inpatients discharged with symptomatic COVID-19 between February 24, 2020 and August 28, 2021 in mainland France. The primary exposure was preexisting mental disorders assessed from all discharge information recorded over the last 9 years (dementia, depression, anxiety disorders, schizophrenia, alcohol use disorders, opioid use disorders, Down syndrome, other learning disabilities, and other disorder requiring psychiatric ward admission). The main outcomes were all-cause mortality and access to salvage therapy (intensive-care unit admission or life-saving respiratory support) assessed at 120 days after recorded COVID-19 diagnosis at hospital. Independent associations were analysed in multivariate logistic models. Of 465,750 inpatients with symptomatic COVID-19, 153,870 (33.0%) were recorded with a history of mental disorders. Almost all categories of mental disorders were independently associated with higher mortality risks (except opioid use disorders) and lower salvage therapy rates (except opioid use disorders and Down syndrome). After taking into account the mortality risk predicted at baseline from patient vulnerability (including older age and severe somatic comorbidities), excess mortality risks due to caseload surges in hospitals were +5.0% (95% confidence interval (CI), 4.7 to 5.2) in patients without mental disorders (for a predicted risk of 13.3% [95% CI, 13.2 to 13.4] at baseline) and significantly higher in patients with mental disorders (+9.3% [95% CI, 8.9 to 9.8] for a predicted risk of 21.2% [95% CI, 21.0 to 21.4] at baseline). In contrast, salvage therapy rates during caseload surges in hospitals were significantly higher than expected in patients without mental disorders (+4.2% [95% CI, 3.8 to 4.5]) and lower in patients with mental disorders (−4.1% [95% CI, −4.4; −3.7]) for predicted rates similar at baseline (18.8% [95% CI, 18.7-18.9] and 18.0% [95% CI, 17.9-18.2], respectively). The main limitations of our study point to the assessment of COVID-19-related mortality at 120 days and potential coding bias of medical information recorded in hospital claims data, although the main study findings were consistently reproduced in multiple sensitivity analyses.
COVID-19 patients with mental disorders had lower odds of accessing salvage therapy, suggesting that life-saving measures at French hospitals were disproportionately denied to patients with mental disorders in this exceptional context.

An Economic Perspective on EpidemiologyBook chapterStéphane Luchini, Patrick Pintus and Miriam Teschl, In: Markt, Staat, Gesellschaft: Eine Festschrift für Richard Sturn, R. Dujmovits, E. Fehr, Ch. Gehrke and H. Kurz (Eds.), 2022-10, pp. 241-254, Metropolis Verlag, 2022
Pareto rationalizability by two single-peaked preferencesJournal articleRicardo Arlegi and Miriam Teschl, Mathematical Social Sciences, Volume 118, pp. 1-11, 2022

We study, in a finite setting, the problem of Pareto rationalizability of choice functions by means of a preference profile that is single-peaked with respect to an exogenously given linear order over the alternatives. This problem requires a new condition to be added to those that characterize Pareto rationalizability in the general domain of orders (Moulin (1985)). This new condition appeals to the existence of a central range of options such that the choice function excludes alternatives which are distant from that range.

Ce que nous voulons et pouvons savoir lors d’une pandémieBook chapterStéphane Luchini, Patrick Pintus and Miriam Teschl, In: Carnet de l'EHESS : Perspectives sur le Coronavirus, 2021-09, pp. 87-91, EHESS, 2021

Comment mesurer le plus finement possible l'accélération ou la décélération d'une épidémie ?

Tracking the dynamics and allocating tests for COVID-19 in real-time: An acceleration index with an application to French age groups and départementsJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Patrick A. Pintus and Miriam Teschl, PLoS ONE, Volume 16, Issue 6, pp. e0252443, 2021

An acceleration index is proposed as a novel indicator to track the dynamics of COVID-19 in real-time. Using data on cases and tests in France for the period between the first and second lock-downs—May 13 to October 25, 2020—our acceleration index shows that the pandemic resurgence can be dated to begin around July 7. It uncovers that the pandemic acceleration was stronger than national average for the [59–68] and especially the 69 and older age groups since early September, the latter being associated with the strongest acceleration index, as of October 25. In contrast, acceleration among the [19–28] age group was the lowest and is about half that of the [69–78]. In addition, we propose an algorithm to allocate tests among French “départements” (roughly counties), based on both the acceleration index and the feedback effect of testing. Our acceleration-based allocation differs from the actual distribution over French territories, which is population-based. We argue that both our acceleration index and our allocation algorithm are useful tools to guide public health policies as France might possibly enter a third lock-down period with indeterminate duration.

Sub-national allocation of COVID-19 tests: An efficiency criterion with an application to Italian regionsJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Patrick A. Pintus and Miriam Teschl, Covid Economics, Volume 12, pp. 192-209, 2020

Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.Mickael Degoule

Evolutionary behavioral economicsBook chapterTerence C. Burnham, Stephen E. G. Lea, Adrian V. Bell, Herbert Gintis, Paul W. Glimcher, Robert Kurzban, Leonhard Lades, Kevin McCabe, Karthik Panchanathan, Miriam Teschl, et al., In: Complexity and Evolution Toward a New Synthesis for Economics, David S. Wilson and Alan Kirman (Eds.), 2016-08, pp. 113-144, MIT Press, 2016


Individual and Collective Choice and Social WelfareBookStudies in Choice and Welfare, Constanze Binder, Giulio Codognato, Miriam Teschl and Yongsheng Xu (Eds.), 2015-05, Springer Berlin Heidelberg, 2015

The papers in this volume explore various issues relating to theories of individual and collective choice, and theories of social welfare. The topics include individual and collective rationality, motivation and intention in economics, coercion, public goods, climate change, and voting theory. The book offers an excellent overview over latest research in these fields.