Cost benefit analysis and the theory of fuzzy decisions : fuzzy value theory The Theory of Fuzzy Optimal and Approximate Social Prices. The Theory of Optimal Social Discount Rate. The Theoretical Structure of Cost Benefit Criteria Choice of Project and Discounting Process. The Theory of Fuzzy Present Value (FPV). The Theory of Fuzzy Decisions Optimal Taxation and Cost Benefit Distribution. Toward a Theory of Social Goals and Objective Formation in Cost Benefit Analysis