روش های جایگزین ارزش استخراج غیر بازاری. آیا اساس تنظیمات یکی است؟

We advocate a more formal structural approach for comparing WTP for non-market or pre-test-market goods conveyed by fundamentally different preference elicitation mechanisms. Seven independent samples of respondents were asked to value the identical good. Elicitation methods include one actual purchase and six widely used hypothetical choice formats. Using a common underlying indirect utility function (and stochastic structure) allows data for different elicitation methods to be used independently, compared pair-wise (as in much of the earlier literature) or pooled across all samples in one unified model with heteroscedasticity across elicitation methods. Our differences in estimated WTP for the individual models are typical of earlier findings. However, pooled-data models that allow for heteroscedasticity reveal that while there are substantial differences in the amount of noise in the different samples, a common underlying systematic component of the preference structure cannot be rejected for at least four (and possibly five) of these seven elicitation methods.

Stated preference information is employed by researchers using conjoint analysis Žin the marketing and transportation literatures. and contingent valuation methods Žin the environmental and health literatures.. A longstanding observation in both these contexts is that different methods of eliciting values often appear to provide systematically different value estimates for the pre-test-market or non-market good in question. Furthermore, these stated preference values are frequently at odds with the values implied by revealed preferencesthe preferred source of value information where markets exist.

For almost two decades, researchers in several disciplines have been puzzled by discrepancies among the empirically estimated values of pre-test-market or nonmarket goods across different elicitation methods used to assess these values. Many past comparisons have been hampered by the need to use samples collected at substantially different points in time, or from different populations, or via survey instruments that differ in other ways besides just the elicitation method employed. The earliest comparisons involved simply an inspection of the different point estimates of value produced by different methods, without conformable models or any opportunity for rigorous assessment of whether the values are statistically significantly different. We use more than 7000 choices to fit an elaborate specification that pools the data for seven types of elicitation methods.