This paper proposes a model to assess the role of demand elasticity in
mitigating the effects of supply side strategic bidding behaviour in a
spot electricity market. We model the supply side within a Conjectural
Supply Function (CSF) framework, which allows incorporating exogenous
changes in demand elasticity and different levels of competition in a
given market. The impacts of demand responsiveness on the market
performances are studied resorting to a set of
proposed indexes that are applied to a model of the Italian market.