5. Hamsa Bastani, Mohsen Bayati, "Online Decision-Making with High-Dimensional Covariates"
Working Paper.

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 correctly doses a majority of patients compared to both existing bandit methods as well as current physician practice.

4. Hamsa Bastani, Joel Goh, Mohsen Bayati, "Evidence of Strategic Behavior in Medicare Claims Reporting"
Winner of 2015 Health Applications Society Best Student Paper Award.
Revised & Resubmitted to Management Science.

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.

3. Hamsa Bastani, Mohsen Bayati, Mark Braverman, Ramki Gummadi, Ramesh Johari, "Analysis of Medicare's Hybrid Pay-for-Performance Contracts"
Working Paper. Draft available upon request.

Medicare's recent initiatives integrate small pay-for-performance incentives with traditional fee-for-service payments. We analyze this class of mechanisms under a principal-agent model with asymmetric information, and characterize the optimal contract. Our results suggest that small performance-based payments can dramatically improve efficiency, and we make several policy design recommendations for Medicare to further improve outcomes.

2. Hamsa Sridhar, Martin Cohen, John Noe, "Creating Optical Vortex Modes with a Single Cylinder Lens," Proc. SPIE 7613 (2010).

1. Charles Camp, Siva Yegnanarayanan, Ali Eftekhar, Hamsa Sridhar, Ali Adibi, "Multiplex coherent anti-Stokes Raman scattering (MCARS) for chemically sensitive, label-free flow cytometry," Opt. Express 17, 22879-22889 (2009).