Optimal transmission regulation of an integrated energy market

► I model the optimal number of regulators and system operators in a multi-national energy market. ► The goal is to balance network reliability against maintenance cost and operator rent. ► A common regulator is optimal if and only if it is able to balance national interests. ► A common system operator is optimal under network complementarity. ► Multiple system operators are optimal if networks are substitutes and the social cost of rent low.