Equation (8) is the only price-elasticity estimate in the paper and is the model used for all subsequent recursive-bootstrap forecasting; it is the paper's operative demand model || 'a model for average demand is specified and estimated using OLS over 1963-1982 as ... - 0.3887 log(P_t) ...' (p.208)
Veall, M. R. (1987): “Bootstrapping the Probability Distribution of Peak Electricity Demand.” International Economic Review 28(1), 203-212