Why are different estimates of the effective reproductive number so different? A case study on COVID-19 in Germany

The effective reproductive number R$_t$ has taken a central role in the scientific, political, and public discussion during the COVID-19 pandemic, with numerous real-time estimates of this quantity routinely published. Disagreement between estimates can be substantial and may lead to confusion among decision-makers and the general public. In this work, we compare different estimates of the national-level effective reproductive number of COVID-19 in Germany in 2020 and 2021. We consider the agreement between estimates from the same method but published at different time points (within-method agreement) as well as retrospective agreement across eight different approaches (between-method agreement). Concerning the former, estimates from some methods are very stable over time and hardly subject to revisions, while others display considerable fluctuations. To evaluate between-method agreement, we reproduce the estimates generated by different groups using a variety of statistical approaches, standardizing analytical choices to assess how they contribute to the observed disagreement. These analytical choices include the data source, data pre-processing, assumed generation time distribution, statistical tuning parameters, and various delay distributions. We find that in practice, these auxiliary choices in the estimation of R$_t$ may affect results at least as strongly as the selection of the statistical approach. They should thus be communicated transparently along with the estimates

Why are different estimates of the effective reproductive number so different? A case study on COVID-19 in Germany.

The effective reproductive number Rt has taken a central role in the scientific, political, and public discussion during the COVID-19 pandemic, with numerous real-time estimates of this quantity routinely published. Disagreement between estimates can be substantial and may lead to confusion among decision-makers and the general public. In this work, we compare different estimates of the national-level effective reproductive number of COVID-19 in Germany in 2020 and 2021. We consider the agreement between estimates from the same method but published at different time points (within-method agreement) as well as retrospective agreement across eight different approaches (between-method agreement). Concerning the former, estimates from some methods are very stable over time and hardly subject to revisions, while others display considerable fluctuations. To evaluate between-method agreement, we reproduce the estimates generated by different groups using a variety of statistical approaches, standardizing analytical choices to assess how they contribute to the observed disagreement. These analytical choices include the data source, data pre-processing, assumed generation time distribution, statistical tuning parameters, and various delay distributions. We find that in practice, these auxiliary choices in the estimation of Rt may affect results at least as strongly as the selection of the statistical approach. They should thus be communicated transparently along with the estimates

Storypotenziale, Stories und Storytelling in der Organisationskommunikation

Storytelling könne traditionelle Marketingmethoden so gut ergänzen und ersetzen, weil „alle Menschen wissen, was eine Geschichte ist“, schreibt Werner T. Fuchs in seinem Praxisbuch ‚Warum das Gehirn Geschichten liebt‘ (2009, 56). Dieser Satz ging mir als storytellinginteressierte Forscherin und Lektorin sowie Betreuerin zahlreicher Abschlussarbeiten zu diesem Themenbereich monatelang durch den Kopf. Tatsächlich zeigte sich, dass Studierende in Lehrveranstaltungen sofort eine Assoziation dazu hervorbrachten, was eine Geschichte ist und eine idealtypische Geschichte (meist ein Märchen) auf Lager hatten. Genauso selbstverständlich reagierten in Praxisgesprächen UnternehmenskommunikatorInnen und deren BeraterInnen. Storytelling, so ihre Sicht, sei ein so alter Hut, da möchte man ja nicht einmal den Ausdruck in den Mund nehmen. Storytelling sei etwas, das sie ohnehin täglich praktizierten.Informationstechnologie und Informationsmanagemen

Comparison of uncertainty intervals after standardization of analytical choices.

The figure shows 95% uncertainty intervals corresponding to Fig 6, Step 4.</p

Temporal coherence of <i>R</i>_<i>t</i> estimates.

Panels: A Proportion of 95% uncertainty intervals issued in real-time which contained the consolidated estimate. B Mean width of 95%-uncertainty intervals (unavailable for HZI, who only published point estimates). C Mean absolute difference of the real-time and consolidated estimates. D Same as C, but signed rather than absolute differences. E Proportions of cases in which real-time and consolidated point estimates disagree on whether Rt > 1. F Same as D, but with a tolerance region [0.97, 1.03], i.e., only instances where real-time and consolidated estimates are on different sides of this interval are counted. All indicators are shown as a function of the time between the target date (as stated by the teams) and the publication date. Averages refer to the period October 1, 2020—July 22, 2021 (see Fig F in S1 Text for exact periods during which methods were operated). The consolidated estimate corresponds to the one published 70 days after the respective target date. For ETH two additional lines are included in the top row differentiating between intervals obtained from the old procedure before January 26, 2021 (n = 95), and from the new bootstrap approach afterward (n = 171; see model description in Section 2.2).</p