Combining Density Forecasts using Bayesian Opinion Pools.
Job Market Paper
Justine Lambert Prize 2024 (Department of Logic and Philosophy, University of California, Irvine)
Best Econometric Paper Award 2023 (Department of Economics, University of California, Irvine)
Abstract: The paper considers the efficient estimation of opinion pools in the Bayesian paradigm and extends their application to cases where the number of competing models exceeds the number of observations. An appropriate Bayesian formulation and estimation algorithm is proposed which allows the weights to shrink towards any possible combination. This flexibility makes the Bayesian opinion pool relevant for applications related to model averaging and model selection and improves stability compared to the ones estimated using scoring rules in a small sample setting. Results from a simulation study reveal that the proposed Bayesian opinion pool methodology improves prediction accuracy. An application involving the Survey of Professional Forecasters demonstrates that the Bayesian opinion pool’s inflation forecast competes well with the equal-weight aggregated inflation forecast published by the Federal Bank of Philadelphia. The application showcases the usefulness of the Bayesian solution in situations where optimization-based opinion pools fail.