Pricing Contractual Vagueness

Abstract

Contract contingency clauses allocate losses from novel disruptions while leaving courts room to interpret their terms. This article separates ambiguity about the event from ambiguity created by open-ended language and prices their interaction in force majeure and material-adverse-change drafting. Within a maintained threshold family, more openness expands guaranteed relief but widens the contested interpretive band. The design has a unique optimum, interior under stated endpoint conditions. Expected utility already generates this trade-off and reproduces the main pricing, dispute, design and adoption choices. Alpha-maxmin is kept as an interpretation. Both parties share one set of possible distributions, and each party’s worst-case weight is an attitude toward that set, not a belief. Two restrictions are assumed, not derived. Each party weights its own adverse reading at least as heavily as the favorable one, and one weight per party serves pricing, dispute, design and adoption. With positive ambiguity about severity scale, no common severity belief reproduces both parties’ valuations across the entire positive-openness fixed-reading standard family unless their worst-case weights sum to one. Separate beliefs can do so. Matching one party’s valuations of precision and standards presents a different obstruction whose scope depends on the admitted belief class. Welfare is evaluated through dollar certainty equivalents without choosing whose probabilities are correct. The model organizes Delaware doctrine and supports conditional proposals for indexed triggers and bounded renegotiation, subject to omitted implementation costs. Transaction evidence illustrates the mechanisms but does not identify ambiguity attitudes.

How the inquiry is constructed

A formal contract-design and bargaining model begins with expected utility, which reproduces the main pricing, dispute, design and adoption choices. Alpha-maxmin adds an interpretation of attitudes toward a shared set of possible probabilities, with separate tests of whether particular beliefs can reproduce the parties' valuations. The analysis uses risk-neutral parties, a specified family of threshold clauses, proofs and illustrative numerical examples. Delaware material-adverse-effect cases and transaction records illustrate the mechanisms; they do not establish parties' ambiguity attitudes. Proposed reforms are conditional because their implementation costs are not modeled, and judicial interpretation remains a research question.

What the analysis establishes

• Open-ended clauses trade wider guaranteed relief from severe disruptions for a larger range of disputed interpretations.
• Expected utility can reproduce the main choice results. Alpha-maxmin supplies an attitude interpretation under stated assumptions, rather than a necessary explanation for the design trade-off.
• Within the specified threshold-clause family, the best degree of openness is unique and lies between precision and maximum openness under the stated endpoint conditions; the model does not rank every alternative drafting instrument.
• Unequal valuations or bargaining weights can shift prices and renegotiated terms. Transfers between the parties are distinct from their combined loss of value and the resources spent disputing.
• Measurable triggers and bounded renegotiation are conditional design proposals whose practical costs require further evaluation. The model does not establish an optimal rule of judicial interpretation.