Measuring values: A conceptual framework for interpreting transactions with special reference to contingent valuation of visibility

People express their value for a good when they pay something for it. Interpretinggood andpayment very broadly, we offer a general analytical framework for characterizing such transactions. This framework is suitable for interpreting actual transactions as well as for creating hypothetical transactions for research purposes. It is described here both in general terms and with special application to one particular kind of transaction, contingent valuation studies in which individuals estimate the value of possible changes in atmospheric visibility. In these transactions, as in many others, risk (of undesired changes in visibility) is one principal feature; at least some uncertainty often surrounds other transaction features as well (For example: How much will visibility really change if I promise to pay for it? Will I really have to pay?). The framework presented here conceptualizes any transaction as involving (a) a good, (b) a payment, and (c) a social context within which the transaction is conducted. Each of these aspects in turn has a variety of features that might and in some cases should affect evaluations. For each such feature, the framework considers first the meaning of alternative specifications and then the difficulties of ensuring that they are understood and evaluated properly. As a whole, the framework provides an integrated approach to designing evaluation studies and interpreting their results.     

VARIABLE SELECTION ALONG CANONICAL VECTORS

When describing and displaying inter-group relationships using canonical variate analysis, the question often arises: which variables contribute most to the group separation along particular canonical vectors? This problem is discussed in the context of an example which uses remotely sensed data to discriminate between cover classes. The appropriate between-groups matrix to be input into subset selection procedures is identified. When combined with subsequent simplification of the vectors, the approach leads to a simpler interpretation of the canonical variate display.