EU-US relations have been marked by a significant volume of trade and close diplomatic ties for most of post-WWII history. Together the EU and US currently account for half of world GDP and a third of global trade (EU Commission Trade Department). The first transatlantic regulatory cooperation agreement was signed 1991 in the area of competition (Pollack, 2003, p.33). Nonetheless, despite strong efforts to achieve convergence, legal enforcement in this field is still marked by stark ideational differences on either side of the Atlantic. In this blog post Daniel Andersen argues that the US and the EU have completely opposing views on corporate monopolies, which manifests itself in the politics of anti-trust legislation, and can be traced to the economic philosophy of ordoliberalism.