Authors emphasize the full-sample (1948-90) model as their headline current-perspective estimate and explicitly discuss the change from the 1948-75 to the 1948-90 span; the 1948-90 own-price coefficient (-0.066) is the estimate on the complete data used for the main forecasts || 'There is a substantial (67%) reduction in the size of the coefficient (-0.199 to -0.066) over the two time spans 1948-75, and 1948-90.' and 'Using data through 1990 to estimate the SEMTSA model, forecasts... are much higher than the forecasts published by NERC' (p.5-6/16, Conclusions)
Kokkelenberg, E. C. and T.D. Mount (1993): “Oil Shocks and the Demand for Electricity.” The Energy Journal 14(2), 113-139