Ethan Che @ Columbia

Ethan Che

PhD Student, Columbia Business School
Decision, Risk, and Operations

I am a PhD student at Columbia Business School in the Decision, Risk, and Operations division. I am advised by Jing Dong and Hongseok Namkoong.

I worked as an ML engineer intern at Instacart in Spring 2023 working on causal machine learning. In Summer 2024, I was an ML Research intern at Netflix working on bandit exploration and uncertainty quantification.

Papers Under Review

	Optimization of Epsilon-Greedy Exploration Ethan Che, Hakan Ceylan, James McInerney, and Nathan Kallus Selected for presentation at MIT Conference on Digital Experimentation (CODE), 2024 arXiv:2506.03324 [cs.LG], 2025 arXiv
	How Well do LLMs Compress Their Own Chain-of-Thought? A Token Complexity Approach Ayeong Lee^, Ethan Che^, and Tianyi Peng arXiv:2503.01141 [cs.CL], 2025 arXiv
	Differentiable Discrete Event Simulation for Queuing Network Control Ethan Che, Jing Dong, and Hongseok Namkoong arXiv:2409.03740 [cs.LG], 2024 Preliminary version in ICML 2023 Differentiable Almost Everything Workshop arXiv workshop
	Mathematical Programming for Adaptive Experiments Ethan Che, Daniel R. Jiang, Hongseok Namkoong, Jimmy Wang arXiv:2408.04570 [cs.LG], 2024 Preliminary version in ESIF Economics and AI+ML Meeting 2024 (33% acceptance rate) Selected for presentation at MIT Conference on Digital Experimentation (CODE), 2024 arXiv workshop
	Adaptive Experimentation at Scale: A Computational Framework for Flexible Batches Ethan Che and Hongseok Namkoong arXiv:2303.11582 [cs.LG], 2023 Major Revision at Operations Research. arXiv
	Stochastic Gradient Descent with Adaptive Data Ethan Che, Jing Dong, and Xin T. Tong arXiv:2410.01195 [cs.LG], 2024 Major Revision at Operations Research. arXiv
	AExGym: Benchmarks and Environments for Adaptive Experimentation Jimmy Wang, Ethan Che, Daniel R. Jiang, and Hongseok Namkoong arXiv:2408.04531 [cs.LG], 2024 arXiv

Ethan Che

PhD Student, Columbia Business School
Decision, Risk, and Operations

Papers Under Review

Work in Progress

Publications

Talks

	QGym: Scalable Simulation and Benchmarking of Queuing Network Controllers Haozhe Chen^, Ang Li^, Ethan Che^, Tianyi Peng, Jing Dong, Hongseok Namkoong NeurIPS 2024 Datasets and Benchmarks Track* arXiv
	Robustly Optimal Auction Design under Mean Constraints Ethan Che arXiv:1911.07103 [econ.TH], 2022 EC '22: Proceedings of the 23rd ACM Conference on Economics and Computation arXiv conference

Ethan Che

PhD Student, Columbia Business School Decision, Risk, and Operations

Papers Under Review

Work in Progress

Publications

Talks

PhD Student, Columbia Business School
Decision, Risk, and Operations