This paper demonstrates that the data from a single market with nonlinear prices are consistent with a large set of underlying structural equations. By restricting the permitted functional form of the structural equations, the nonlinearity of marginal prices can be used to identify the price and shift parameters of a single member from the set. The identification approach must be used with great caution, however, because the true shape of supply and demand functions is often unknown and so the necessary restrictions may be unjustified.

Whenever marginal prices are nonconstant, as in most hedonic and household production function markets, ordinary least squares estimates of the price elasticities of structural equations will be biased. A two-stage least squares estimation procedure is developed and applied to estimate hedonic (and potentially household production function) demand functions when price gradients are nonlinear.

The hedonic travel cost method is a technique which reveals how much users are willing to pay for the individual characteristics of outdoor recreation sites. The prices of recreation attributes are estimated by regressing travel costs on the bundles of characteristics associated with each of several potential destination sites. The demand for site characteristics on site quality is then revealed by comparing the site selection of users facing different attribute prices. The technique is applied to value steelhead fish density in Washington State streams.