The Yale Law Journal

VOLUME
122
2012-2013
NUMBER
5
March 2013
1104-1371
Essay

Reconceptualizing the Burden of Proof

Edward K. Cheng


122 Yale L.J. 1254 (2013).

The preponderance standard is conventionally described as an absolute probability threshold of 0.5. This Essay argues that this absolute characterization of the burden of proof is wrong. Rather than focusing on an absolute threshold, the Essay reconceptualizes the preponderance standard as a probability ratio and shows how doing so eliminates many of the classical problems associated with probabilistic theories of evidence. Using probability ratios eliminates the so-called Conjunction Paradox, and developing the ratio tests under a Bayesian perspective further explains the Blue Bus problem and other puzzles surrounding statistical evidence. By harmonizing probabilistic theories of proof with recent critiques advocating for abductive models (inference to the best explanation), the Essay bridges a contentious rift in current evidence scholarship.