Johannes Bracher – personal website

I am currently an Emmy Noether independent junior research group leader at Karlsruhe Institute of Technology, Germany. I am moreover affiliated with the Computational Statistics Group at Heidelberg Institute for Theoretical Studies and serve as a PI in the Helmholtz Information and Data Science School for Health. You can also find me on my institutional website, Google Scholar, mastodon, Twitter.

My email address is [my first name].[my last name]@kit.edu.

Open positions

I will likely hire a PhD student in 2024. Do not hesitate to get in touch if you are interested. If you are interested in a BSc or MSc thesis at KIT likewise get in touch by email.

Research Interests

• Epidemic forecasting
• Forecast evaluation
• Count time series modelling

Short Bio

• since 2023: Junior Research Group Leader, Karlsruhe Institute of Technology.
• since 2020: guest researcher, Computational Statistics Group, Heidelberg Institute for Theoretical Studies
• 2020-2023: Postdoctoral researcher, Chair of Statistics and Econometrics, Karlsruhe Institute of Technology. Funding: Helmholtz Information & Data Science Pilot Project SIMCARD.
• 2020: PhD Epidemiology and Biostatistics, University of Zurich, Switzerland. Thesis title: Statistical modelling and forecsting of infectious disease surveillance counts. Supervisor: Leonhard Held.
• 2016: MSc Statistics, LMU Munich, Germany
• 2013: BA Sociology / Political Science, LMU Munich, Germany
• 2012: BSc Statistics, LMU Munich, Germany

Collaborations

I am or was involved in various collaborative projects on infectious disease forecasting:

• German COVID19 Nowcast Hub with daily nowcasts of the seven-day hospitalization incidence.
• RespiNow Hub nowcasting and short-term forecasting of various respiratory pathogens in Germany (under construction).
• European COVID19 Forecast Hub, led by ECDC and EpiForecasts
• US COVID19 Forecast Hub, led by the Reich Lab at UMass Amherst

Selected papers

See my Google Scholar profile for an up-to-date bibliography.

• Wolffram D, Abbott, […], Bracher J (2023). Collaborative nowcasting of COVID-19 hospitalization incidences in Germany. PLOS Computational Biology 19(8): e1011394. Open access.
• Bosse N, Abbott S, Cori A, van Leeuwen E, Bracher J, Funk S (2023). Scoring epidemiological forecasts on transformed scales. PLOS Computational Biology 19(8): e1011393.
• Cramer EY, Ray EL, Lopez VM, Bracher J et al (2022). Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the US. Proceedings of the National Academy of Sciences 119(15):e2113561119. Open access.
• Bracher J, Wolffram D, Deuschel J, Görgen K, Ketterer J et al (2021). A pre-registered short-term forecasting study of COVID-19 in Germany and Poland during the second wave. Nature Communications, 12:5173. Open access.
• Bracher J, Ray EL, Gneiting T and Reich NG (2020) Evaluating epidemic forecasts in an interval format. PLOS Computational Biology 17(2): e1008618. Open access.
• Bracher, J and Held, L (2020) A marginal moment matching approach for fitting endemic-epidemic models to underreported disease surveillance counts. Biometrics 77(4):1202–1214. Preprint available here.
• Bracher J (2019). On the multibin logarithmic score used in the FluSight competitions. Proceedings of the National Academy of Sciences, 116(42):20809–20810. Free access. Preprint of an extended version available here.

Recent preprints

• Brockhaus E, Wolffram D, […], Bracher J (2023). Why are different estimates of the effective reproductive number so different? A case study on COVID-19 in Germany.
• Bracher J and Littek JM (2023). A statistical assessment of influenza intensity thresholds obtained from the moving epidemic and WHO methods.
• Bracher J, Rueter L, Krueger F, Lerch S, Schienle M (2023): Direction Augmentation in the Evaluation of Armed Conflict Predictions. Accepted at International Interactions.
• Bracher J (2022). A thinning-based representation of the compound-Poisson INGARCH model, with an interpretation as a stochastic epidemic process.

Recent talks

Some slides and recordings from recent talks:

• Score-based evaluation of epidemic forecasts. London, 15 March 2023, Forecasting infectious disease incidence for public health .
• Hoch oder runter? Nowcasting bei COVID-19 (in German). Heidelberg, 9 July 2022, Open Doors Day, Heidelberg Institute for Theoretical Studies.
• Collaborative nowcasting of COVID-19 hospitalization incidences. Hamburg, 31 Mar 2022, DAGStat Conference.
• A marginal moment matching approach for fitting endemic-epidemic models to underreported disease surveillance counts.. London School of Hygiene and Tropical Medicine, 23 Mar 2022, Workshop on the Endemic-Epidemic framework for infectious disease modelling. See also recording here.