We develop and implement a version of the popular "policytree" method (Athey and Wager, 2021) using discrete optimisation techniques. We test the performance of our algorithm in finite samples and find an improvement in the runtime of optimal policy tree learning by a factor of nearly 50 compared to the original version. We provide an R package, "fastpolicytree", for public use.
@article{arxiv.2506.15435,
title = {Fast Learning of Optimal Policy Trees},
author = {James Cussens and Julia Hatamyar and Vishalie Shah and Noemi Kreif},
journal= {arXiv preprint arXiv:2506.15435},
year = {2025}
}