In this paper we investigate the factors contributing to the fall in the Lerner Index (price-cost margin) in the British electricity market during the 90s. A first stage of our analysis models the number of breaks in the Lerner Index and their dating as unknowns. Our results suggest the...

\We analyze the time-series of prices in the Spanish electricity market by means of a time varying-transition-probability Markov switching model. Accounting for changes in demand and cost conditions (which reflect changes in input costs, capacity availability and hydro power), we show that the...