Using Dollars as a Response Scale: 
Magnitude Estimation without a Standard

Daniel Kahneman

The same pattern of results has been observed in two seemingly
different contexts: a large-scale experimental study of the psychology
of punitive awards (Kahneman, Schkade and Sunstein, 1997) and a
reanalysis of hypothetical willingness-to-pay data (Kahneman and
Ritov, 1994).  In both cases dollar responses are strongly correlated
with other measures of attitudes, but much less reliable than
alternative measures.  The source of the unreliability is traced to
the scaling factor that affects the translation from the underlying
attitude to the dollar scale.  The evidence suggests that dollar
responses measure some attitudes on a ratio scale, but the scaling
factor (modulus) adopted by different individuals may be quite
arbitrary.