European Union Single Market: design and development

What precisely is a Single Market, how it has been designed in the case of the European Union (e.g. in the treaty) and how it has developed over 5 decades, are the three questions answered in this contribution. It is first shown that the design of a Single Market matters: it is not just about goods markets (despite the enormous emphasis in the literature on this aspect) but also about services, labour, capital and codified technology. In order to have a Single Market function properly, it is indispensable to combine negative integration (removal of barriers) with a considerable ambition in positive integration (common regulation, selected common policies, common market institutions where appropriate and endowed with proportionate but sometimes overriding powers). The treaty contained a unique design which has been ‘upgraded’ with the increasing ambitions of ‘deepening’ and ‘widening’ of scope of markets and policies in the EU. The development of the EU Single Market is stylized in four accomplished stages after the mid-1980s, when the ‘customs-union-plus’ was overcome for a much ‘deeper’ internal market, until today.