The scope test revisited

Sensitivity to scope has become an acid test for the validity of responses to non-market valuation scenarios. The theoretical relationship between whether a subject's responses exhibit sensitivity to scope and whether consistent preferences underlie those responses is examined. It is found that sensitivity to scope is neither necessary nor sufficient for preference consistency. Moreover, while continuous, strongly monotonic and total preferences yield scope, the converse fails to hold. The results suggest caution in scope's application as a survey validation tool.