Machine Learning in Finance

Speaker: Junting Duan (Stanford University)

Date/Time: Wednesday, 3/4, 7:00pm CET (10:00am PST, 1:00pm EST)

Title: Imputation-Powered Inference for Missing Covariates

Abstract: Missing covariate data is a prevalent problem in empirical research. We provide a novel framework for handling missing covariate data for estimation and inference in downstream tasks. Our general framework provides an automatic and easy-to-use pipeline for empirical researchers: First, missing values are imputed using virtually any imputation method under general observation patterns. Second, we automatically correct for the imputation bias and adaptively weight the imputed values according to their quality. Third, we use all available data, including imputed observations, to obtain more precise point estimates for the downstream task with valid confidence intervals. Our approach ensures valid inference while improving statistical efficiency by leveraging all available data. We establish the asymptotic normality of the proposed estimator under general missing data patterns and a broad class of imputation methods. Through simulations, we demonstrate the superior performance of our approach over natural benchmarks, as it achieves both lower bias and variance while being robust to imputation quality. In a comprehensive empirical study of the dependence of equity markets on carbon emissions, we show that properly accounting for missing emissions data yields no evidence of correlation between stock returns and emissions directly produced by companies, but a negative correlation with value chain emissions.

Speaker: Jonathan Tam (University of Oxford)

Date/Time: Wednesday, 3/4, 7:00pm CET (10:00am PST, 1:00pm EST)

Title: Extended mean field control: a global numerical solution via finite-dimensional approximation

Abstract: We present a finite-dimensional global numerical approximation for a class of extended mean field control problems. Our algorithm learns the value function on the whole Wasserstein domain, as opposed to a fixed initial condition. We leverage the approximation of the mean field problem by a finite-player cooperative optimisation problem, due to the propagation of chaos, together with the usage of finite-dimensional solvers. This avoids the need to directly approximate functions on an infinite-dimensional domain, and allows for more efficient memory usage and faster computation. 

Joint work with Athena Picarelli and Marco Scaratti (University of Verona).