Authors endorse Table 4 as a whole: 'the price and income elasticities presented in Table 4 are within the range of commonly accepted values' and 'the Hausman method produces results which are perfectly credible' (p.3/70); middle strata = largest subsample (n=546).
Maddock, R., & Castano, E. (1991): 'The welfare impact of rising block pricing: Electricity in Colombia.' The Energy Journal, 12(4), 65-77.