Private Law Theory

Abstract
The counterfactual, or ‘but for’, model of causation is pervasive in tort law for proving factual causation. It asks whether the harm suffered by the plaintiff would have occurred in the absence of the defendant’s misconduct. In one category of cases, however, the but-for model is said to fail: cases involving multiple sufficient causes (eg, where two independent fires merge to destroy a lodge, where each fire would alone be sufficient to destroy it). Courts have rejected the but-for standard in these circumstances as yielding results that are contrary to common intuition, court decisions, and public policy; and numerous scholars have called for altogether abandoning it as a theory of causation, due to its purported failings in these circumstances. In this article, I argue that the widespread disapproval of the but-for model, as it applies to cases involving multiple sufficient causes, is misplaced. I apply a predominant counterfactual framework for cause and effect in statistics and the sciences – one that mirrors the but-for model of causation in law – to show that, contrary to the common view that the but-for model fails in cases involving multiple sufficient causes, a nuanced approach to this conception of causation leads to the opposite conclusion, and it produces results that are indeed consistent with common intuition and the decisions of the courts.

Bavli, Hillel, Counterfactual Causation in Tort Law (September 4, 2018).

First posted 2018-09-06 06:03:45