Céline Cunen: Scoring forecasts of conflict fatalities with MSE: to log or not to log

Céline Cunen is a researcher at the Oslo Centre for Biostatistics and Epidemiology (OCBE) at the Oslo University Hospital. There she works on a variety of topics within methodological and applied statistics, including clinical trials. She also holds a part-time position at Peace Research Institute Oslo (PRIO) where she does research on the evaluation of conflict forecasts. She received her PhD in statistics from the University of Oslo in 2018.

Bildet kan inneholde: smil, erme, lykke, panne, snipp.

Credit: Aina Louise C. Haukeland

Several existing forecasting systems attempt to predict various forms of political violence, like conflict fatalities, in the near future. Researchers and end-users of such forecasts prefer ‘risky’, over-predicting forecasts rather than careful, under-predicting ones. Within this community many believe that selecting forecasts using the mean-squared error on the log-scale (MSLE) rather than on the original scale (MSE) will lead to the selection of a riskier forecast. In this talk, we study this ‘conventional wisdom’. We discuss different interpretations and investigate their validity, while placing particular emphasis on data distributions which are typical in the political violence context – with many zeroes, and a long tail.

This talk is based on joint work with Gudmund Hermansen, Håvard Hegre and Michael Colaresi.

Published Sep. 17, 2026 4:15 PM - Last modified Sep. 17, 2026 4:15 PM