Beyond forecast leaderboards: Measuring individual model importance based on contribution to ensemble accuracy

Fuente: arXiv
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Bibliographic Details
Main Authors: Kim, Minsu, Ray, Evan L., Reich, Nicholas G.
Format: Preprint
Published: 2024
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author Kim, Minsu
Ray, Evan L.
Reich, Nicholas G.
author_facet Kim, Minsu
Ray, Evan L.
Reich, Nicholas G.
contents Ensemble forecasts often outperform forecasts from individual standalone models, and have been used to support decision-making and policy planning in various fields. As collaborative forecasting efforts to create effective ensembles grow, so does interest in understanding individual models' relative importance in the ensemble. To this end, we propose two practical methods that measure the difference between ensemble performance when a given model is or is not included in the ensemble: a leave-one-model-out algorithm and a leave-all-subsets-of-models-out algorithm, which is based on the Shapley value. We explore the relationship between these metrics, forecast accuracy, and the similarity of errors, both analytically and through simulations. We illustrate this measure of the value a component model adds to an ensemble in the presence of other models using US COVID-19 death probabilistic forecasts. This study offers valuable insight into individual models' unique features within an ensemble, which standard accuracy metrics alone cannot reveal.
format Preprint
id arxiv_https___arxiv_org_abs_2412_08916
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Beyond forecast leaderboards: Measuring individual model importance based on contribution to ensemble accuracy
Kim, Minsu
Ray, Evan L.
Reich, Nicholas G.
Methodology
Ensemble forecasts often outperform forecasts from individual standalone models, and have been used to support decision-making and policy planning in various fields. As collaborative forecasting efforts to create effective ensembles grow, so does interest in understanding individual models' relative importance in the ensemble. To this end, we propose two practical methods that measure the difference between ensemble performance when a given model is or is not included in the ensemble: a leave-one-model-out algorithm and a leave-all-subsets-of-models-out algorithm, which is based on the Shapley value. We explore the relationship between these metrics, forecast accuracy, and the similarity of errors, both analytically and through simulations. We illustrate this measure of the value a component model adds to an ensemble in the presence of other models using US COVID-19 death probabilistic forecasts. This study offers valuable insight into individual models' unique features within an ensemble, which standard accuracy metrics alone cannot reveal.
title Beyond forecast leaderboards: Measuring individual model importance based on contribution to ensemble accuracy
topic Methodology
url https://arxiv.org/abs/2412.08916