No single headline own-price elasticity; the paper's thesis is the CHANGE in price elasticity across periods (demand transformation). The treatment-period, strong-commitment (S) coefficients represent the most recent transformed demand behavior the paper emphasizes. || 'demand has, in fact, become more price elastic from the base to the treatment period for both residential and both commercial groups, and for the strong program commitment states in the industrial sector' (p.106)
Horowitz, M. J. (2007): “Changes in Electricity Demand in the United States from the 1970s to 2003," The Energy Journal 28(3), 93-119