Wald-type specification tests select the TVC cointegration model over the FC model ("which specification was rejected", p. 18); in the preferred TVC model prices are insignificant for residential and commercial, leaving the TVC industrial price elasticity (~-0.05, Table 3) as the only author-endorsed price estimate; FC rows 900108-900110 are explicitly dispreferred. || "According to our results in Table 3, the price elasticity of the industrial electricity demand is around −0.05, which is not nearly as big as those reported for other countries in earlier studies relying on the models with fixed coefficients, and also those produced by the fixed coefficient model estimated from our Mexican data." (p. 19, printed page)
Chang, Y., & Martinez-Chombo, E. (2003): 'Electricity demand analysis using cointegration and error-correction models with time varying parameters: The Mexican case.' Working paper, Rice University.