More regulation, not less, is temporarily necessary, if effective competition is to be established in network industries. This paradox places new requirements on computable models: they should provide realistic descriptions of technologies but also of markets and institutions. Industrial economics and computation of economic equilibrium can help achieve this dual requirement. This paper discusses their potential in the context of the deregulation of the European gas and electricity sectors. Some key elements of the European legislative process are first presented in order to point out the diversity of institutions that can emerge and to highlight the need to model institutions. Perfect competition equilibrium models although institutionally poor are argued to be useful for ex post analysis. Applications of the standard Cournot and Bertrand paradigms in ex ante analysis of gas and electricity markets are reviewed next. Models combining market power and externalities are then discussed with reference to electricity restructuring. Finally multistage equilibrium models are introduced in the context of investment in gas and electricity. Computation remarks conclude the paper.