How serious are expressions of protected values?

People think that some things that they value should be protected from trade-offs with other things. For example, people think that no economic gain is great enough to justify clear-cutting old-growth forest. The authors probed the stability of these protected values (PVs) in several ways. Subjects were asked to think of counterexamples, and this had some effect on PVs. Subjects were then asked how they would resolve conflicts between 2 PVs. Resolutions did not differ from those between other values, but subjects tended to feel that conflicts between PVs did not occur in reality. Despite people's claims that PVs are unchanged by variation in quantity, expression of PVs was reduced when the magnitude or probability of the violation of a PV was smaller. In summary, PVs appear to be labile and amenable to challenge. Despite earlier concerns, apparent PVs may not always preclude the use of valuation measures in cost-effectiveness analysis or negotiated agreement on controversial issues.