Hsing explicitly selects the CSCTWA model over OLS and CSHTWA ("yields more efficient estimates as the estimated standard errors are smaller than those in the other two models", p. 260) and the abstract is built around it; the SR price elasticity -0.239 and its LR twin -0.543 are the numbers the narrative revolves around, so both CSCTWA rows are preferred while the OLS (900434) and CSHTWA (900435) columns are comparison specifications. || "Based on the CSCTWA model, the short-run demand elasticities are the estimated coefficients because of the use of the log-linear form. For example, the short-run price and income elasticities are -0.239 and 0.397, respectively. The long-run elasticities of demand with respect to the own-price, income, and the price of natural gas are estimated to be -0.543, 0.902, and 0.325, respectively." (p. 260)
Hsing, Y. (1994): 'Estimation of residential demand for electricity with the cross-sectionally correlated and time-wise autoregressive model.' Resource and Energy Economics, 16, 255-263.