Natural Counterfactuals With Necessary Backtracking

Guang-Yuan Hao, Jiji Zhang, Biwei Huang, Hao Wang, Kun Zhang

Keywords: causal model, counterfactual reasoning, counterfactual generation, normalizing flows

TL;DR: We propose a framework of natural counterfactuals and a method for generating counterfactuals that are more feasible with respect to the actual data distribution.

Abstract: Counterfactual reasoning is pivotal in human cognition and especially important for providing explanations and making decisions. While Judea Pearl's influential approach is theoretically elegant, its generation of a counterfactual scenario often requires too much deviation from the observed scenarios to be feasible, as we show using simple examples. To mitigate this difficulty, we propose a framework of natural counterfactuals and a method for generating counterfactuals that are more feasible with respect to the actual data distribution. Our methodology incorporates a certain amount of backtracking when needed, allowing changes in causally preceding variables to minimize deviations from realistic scenarios. Specifically, we introduce a novel optimization framework that permits but also controls the extent of backtracking with a "naturalness'' criterion. Empirical experiments demonstrate the effectiveness of our method. The code is available at https://github.com/GuangyuanHao/natural_counterfactuals.

Primary Area: Causal inference

Submission Number: 4096