Working Papers

Choosing A Headline Estimand from Matching, DID, and Hybrid Designs: A Minimax-Regret Approach
Yechan Park and Yuya Sasaki, 2026.
arXiv preprint.
Link

Decomposition of Spillover Effects Under Misspecification: Pseudo-true Estimands and a Local–Global Extension
Yechan Park and Xiaodong Yang, 2026.
arXiv preprint.
Link

A Bracketing Relationship for Long-Term Policy Evaluation with Combined Experimental and Observational Data
Yechan Park and Yuya Sasaki, 2024.
Under Review.
Link

Published Papers

The Informativeness of Combined Experimental and Observational Data under Dynamic Selection
Yechan Park and Yuya Sasaki, 2026.
Journal of Econometrics.
Link

Asymptotic Expansion for Batched Bandits
Yechan Park and Nakahiro Yoshida, 2024.
Statistical Inference for Stochastic Processes (Conditionally Accepted).
Link

Beyond Central Limit Theorem for Higher Order Inference in Batched Bandits
Yechan Park, Nakahiro Yoshida, and Ruohan Zhan, 2022.
Neural Information Processing Systems 2022, Causal Machine Learning for Real-World Impact Workshop.
Link

Work in Progress

Weighing Experimental vs. Observational Evidence: Decision-Relevant Summaries of Treatment Effect Heterogeneity
Isaiah Andrews, Raj Chetty, Yechan Park, and Bas Sanders.

Subsumed/Resting Papers

Matching ≤ Hybrid ≤ Difference in Differences
Yechan Park and Yuya Sasaki, 2024.
Link