Drawing on a new analytical framework provided by the economic theory of optimal legal areas, this paper identifies the factors determining the optimal size of the European Union. It applies this theory to the question of how enlargement affects the welfare of the current and the new members of...

The question of third-party access to the networks has become central to the debate around the liberalisation of the European electricity markets due to the natural monopoly characteristic of the transmission network. The European Union's electricity directive provides three institutional...