Joint Infeasibility of Individually Feasible Tasks: How Tasks That Are Each Possible Can Be Impossible Together

This conceptual paper introduces Joint Infeasibility of Individually Feasible Tasks, the mechanism by which tasks that can each be performed separately become infeasible together because they draw on limited shared resources or require incompatible conditions. It examines the gap between checking commitments individually and testing whether they can all be met under a combined constraint. The account requires an identifiable coupling. Separate feasibility does not establish joint feasibility, but tasks do not conflict merely because they occur together. Assessments must identify the resources or dependencies tasks share, examine when demands are likely to coincide, and test the commitments jointly. The paper also considers how allocation determines who bears a shortfall. The paper relates the mechanism to Diamond and Dybvig’s theory of bank runs and discusses the March 2023 failure of Silicon Valley Bank. The documented case establishes that joint withdrawal demand exceeded available liquidity. It does not establish that every depositor’s full withdrawal would have been feasible in isolation. A complete demonstration of the mechanism would also require evidence of individual feasibility. Part of the Relational Conditions and Dynamics series within On Human Modeling, the paper offers questions for examining shared constraints, simultaneous demands, and the adequacy of separate feasibility checks. It does not prescribe reserve levels or allocation rules.