Proceeding from a basic concept underpinning economic evaluation, opportunity cost, this study aims to explain how different approaches to economics diverge quite dramatically in their ideas of what constitutes appropriate valuation, both in principle and practice. Because the concept of opportunity cost does not inherently specify how valuation should be undertaken or specify how appropriate any economic value framework (EVF) might be, the three main economics-based approaches to providing evidence about value for health technology assessment are described.

This paper describes how the three main EVFs—namely, the extra-welfarist, welfarist, and classical—are most typically understood, applied, and promoted. It then provides clarification and assessment of related concepts and terminology.

Although EVFs differ, certain underlying characteristics of valuation were identified as fundamental to all approaches to economic evaluation in practice. The study also suggests that some of the rhetoric and terms employed in relation to the extra-welfarist approach are not wholly justified and, further, that only the welfarist approach ensures adherence to welfare-economic principles. Finally, deliberative analysis, especially when connected with a classical economic approach, can serve as a useful supplement to other analytical approaches.

All three approaches to economic evaluation have something to offer assessment processes, but they all display limitations too. Therefore, the author concludes that the language of economic evaluation should be used with sufficient humility to prevent overselling of EVFs, especially with regard to the qualities of evidence they provide for priority setting processes.