4. Hamsa Bastani, Mohsen Bayati, "Online Decision-Making with High-Dimensional Covariates"
Big data has enabled decision-makers to personalize decisions at the individual-level. We present an efficient
method to solve this problem in an online setting and a corresponding regret analysis. We provide both
theoretical guarantees and empirical evidence that our algorithm significantly outperforms existing methods.
Furthermore, we illustrate the practical relevance of our algorithm on a real clinical problem of warfarin dosing.
Our algorithm outperforms existing bandit methods as well as physicians to correctly dose a majority of patients.
Upcoding is the practice where medical providers alter claims to receive increased reimbursement. Prior studies on upcoding have been limited by unobserved confounders (e.g. provider quality and patient risk). We present a novel approach that exploits state-level variations in adverse event regulation and instrumental variables to detect upcoding at a national scale. We also make several policy recommendations for reducing upcoding.