论文标题
未来的反事实
Counterfactuals for the Future
论文作者
论文摘要
反事实通常被描述为“回顾性”，重点是实现过去的假设替代品。此描述涉及对正在建模的系统中外源变量的结构和稳定性的常见隐式假设 - 在使用反事实的许多情况下，这种假设是合理的。在这项工作中，我们考虑了可能对外源变量做出不同假设的情况，即，每个单元的外源噪声项确实表现出某些单位特异性结构和/或稳定性。这导致我们对反事实的不同使用 - 一种“前瞻性”而不是“回顾性”反事实。我们介绍了“反事实治疗选择”，这是一种治疗选择问题，可以激发使用前瞻性反事实。然后，我们探讨了如何与前瞻性的反事实选择方法之间的不匹配，这与对外源噪声的不同假设一致，这可能会导致违反直觉结果。
Counterfactuals are often described as 'retrospective,' focusing on hypothetical alternatives to a realized past. This description relates to an often implicit assumption about the structure and stability of exogenous variables in the system being modeled -- an assumption that is reasonable in many settings where counterfactuals are used. In this work, we consider cases where we might reasonably make a different assumption about exogenous variables, namely, that the exogenous noise terms of each unit do exhibit some unit-specific structure and/or stability. This leads us to a different use of counterfactuals -- a 'forward-looking' rather than 'retrospective' counterfactual. We introduce "counterfactual treatment choice," a type of treatment choice problem that motivates using forward-looking counterfactuals. We then explore how mismatches between interventional versus forward-looking counterfactual approaches to treatment choice, consistent with different assumptions about exogenous noise, can lead to counterintuitive results.
