Representing Rule-Based Presumptions in Legal Decision Documents
Representing the use of rule-based presumptions in legal decision documents, Vern R. Walker. In Law, Probability and Risk, published online May 26, 2014 (print version forthcoming, 2014). Prepublication copy available for download in .pdf format.
This article discusses rule-based presumptions that are authoritatively established, as distinct from other types of presumptions that are generalization-based or policy-based. It first introduces some legal distinctions that are used to define presumptions in law, and then presents extended examples of legal presumptions drawn from the statute and case law governing compensation for vaccine-related injuries in the USA. It proposes a formal method of representing rule-based legal presumptions that utilizes a three-valued, default logic. Finally, it uses the vaccine-injury compensation cases and the concept of legal presumption to explore difficulties in determining the burdens of production and persuasion, the meaning of legal terms in propositions to be proved and the inferences to be drawn from them.