The estimates of the nonlinear preference parameters are generally robust to the choice of instruments. Not surprisingly, the transportation cost and the price coefficients are the most sensitive. The price coefficient leads to an average store-level price elasticity of demand between −10 and −15 depending on the specification. This high elasticity is consistent with the fact that gasoline stations are not highly differentiated from each other, and suggests that consumers are very price sensitive with regard to their purchasing decisions. Notice also that the model is estimated over a period of high price volatility, which possibly overestimates the price sensitivity of consumers