The Systemic Impact Ledger: A Framework for Evaluating Costs and Benefits Across Systems—A Multi-Dimensional Model of Cross-System Evaluation, Time Horizons, and Cost Externalization

The first four papers in the System Logic series established systemic adequacy, boundary and time, local optimization and systemic failure, and feedback and systemic correction as core concepts for evaluating judgments and actions in open systems. Together, they raise a central question: how can the multiple impacts of a judgment or action be evaluated across different systems, time horizons, subjects, and levels? This paper proposes the Systemic Impact Ledger as an evaluative framework for addressing that question. The Systemic Impact Ledger does not reduce all values to a single currency or to physical energy. Instead, it establishes a multi-dimensional recording framework for tracking costs and benefits across subjects, temporal scales, system levels, reversibility conditions, and externalities. The paper distinguishes five core dimensions of impact, proposes a minimal recording structure, and develops a methodological pathway from qualitative recording to semi-quantitative comparison. Its central argument is that the primary function of the Systemic Impact Ledger is not to produce precise numerical totals but to expose cost externalization, temporal displacement, level imbalance, irreversible damage, and feedback blindness. In doing so, it makes systemic adequacy operational, discussable, and testable. The framework is demonstrated through cases from corporate decision-making, public policy, technological development, personal choice, environmental policy, organizational design, and digital platform governance. The paper concludes with theoretical boundaries, falsifiability conditions, and foundations for future research on private–public good transformation, institutional adaptation, and civilizational risk.