Economic theory suggests that willingness to pay for two goods
independently offered should remain unchanged when the survey instrument
changes slightly. Four survey treatments consisting of comprehensive good
and a subset of that good were used. The surveys alternated in the
question ordering and in the embedded good which accompanied the
comprehensive good. We tested for sequencing and instrument context
effects using both a combined and split sample designs. In the combined
sample case we found some evidence to sequencing effects in the data
containing the first subset good. Likelihood ratio tests indicated that
sequencing did not effect scale or location of parameters. In the test for
instrument context effects, evidence was found indicating context does
effect willingness to pay estimates.
