Cross-Fitting-Free Debiased Machine Learning with Multiway Dependence

A new paper introduces a 'cross-fitting-free' method for debiased machine learning (DML) that works with multiway clustered data. This breakthrough eliminates the need for computationally heavy 'cross-fitting,' a standard but inefficient technique. The new approach uses Neyman-orthogonal moment conditions and a novel empirical process method, allowing for valid statistical inference without sample splitting. It promises significant efficiency gains when dealing with complex models and data with multiple dependency structures.