Conformal Prediction under Lévy-Prokhorov Distribution Shifts: Robustness to Local and Global Perturbations

Liviu Aolaritei (UC Berkeley) · Julie Zhu (Massachusetts Institute of Technology) · Oliver Wang (Massachusetts Institute of Technology) · Michael Jordan (University of California, Berkeley) · Youssef Marzouk (Massachusetts Institute of Technology)
confidence levelsconformal predictioncoveragedistribution shiftsglobal perturbationshigh-dimensional distribution shiftsinterval widthlocal perturbationslévy-prokhorov ambiguity setsprediction intervalsrobust conformal predictionscoring functiontotal variationwasserstein metricworst-case quantiles

Conformal prediction provides a powerful framework for constructing prediction intervals with finite-sample guarantees, yet its robustness under distribution shifts remains a significant challenge. This paper addresses this limitation by modeling distribution shifts using Lévy-Prokhorov (LP) ambiguity sets, which capture both local and global perturbations. We provide a self-contained overview of LP ambiguity sets and their connections to popular metrics such as Wasserstein and Total Variation. We show that the link between conformal prediction and LP ambiguity sets is a natural one: by propagating the LP ambiguity set through the scoring function, we reduce complex high-dimensional distribution shifts to manageable one-dimensional distribution shifts, enabling exact quantification of worst-case quantiles and coverage. Building on this analysis, we construct robust conformal prediction intervals that remain valid under distribution shifts, explicitly linking LP parameters to interval width and confidence levels. Experimental results on real-world datasets demonstrate the effectiveness of the proposed approach.