Insufficient Causes

Abstract:     
This article analyzes a difficult causation question. If a force is not independently sufficient to bring about an injury, under what circumstances should a court find the force to be a cause of the injury? The question has practical importance. It frequently arises in litigation involving toxic torts and products liability failure to warn.

The article includes a critique of the NESS test of causation as it pertains to this issue. That test is rapidly emerging as an important supplement to the but for test of causation. Much of the focus of twenty-first century causation scholarship will explore the strengths and weaknesses of the NESS test. A key weakness of the NESS test is its inability adequately to identify when one potential cause preempts another. This article explores this weakness of the NESS test in the context of insufficient causes, and offers important new insights with respect to the limitations of the NESS test. The article also presents the results of an empirical study casting doubt on the claim that the NESS test produces results that are consistent with human intuition about causation.

Keywords: Cause, causation, NESS, but for, substantial factor, tort, omission, sufficient cause, insufficient cause, mutiple sufficient cause, overdetermined cause

Accepted Paper Series