Fiche du document
8 juillet 2019
- 1907.03809
- doi: 10.1093/qje/qjac015
Mots-clés
Economics - Theoretical Economics Computer Science - Machine Learning Economics - Econometrics 62J99, 91B26,Sujets proches
Pattern Model Economic theory Political economyCiter ce document
Jose Luis Montiel Olea et al., « Competing Models », arXiv - économie, ID : 10.1093/qje/qjac015
Métriques
Partage / Export
Résumé
Different agents need to make a prediction. They observe identical data, but have different models: they predict using different explanatory variables. We study which agent believes they have the best predictive ability -- as measured by the smallest subjective posterior mean squared prediction error -- and show how it depends on the sample size. With small samples, we present results suggesting it is an agent using a low-dimensional model. With large samples, it is generally an agent with a high-dimensional model, possibly including irrelevant variables, but never excluding relevant ones. We apply our results to characterize the winning model in an auction of productive assets, to argue that entrepreneurs and investors with simple models will be over-represented in new sectors, and to understand the proliferation of "factors" that explain the cross-sectional variation of expected stock returns in the asset-pricing literature.