In this report under the API we consider the economic relationship between ASEAN and the European Union (EU). The comparison is often made between these two regional blocs, which represent the two leading efforts to integrate their respective regions. The EU’s economic integration is significantly deeper and supported by a far more developed institutional and legal framework. The EU is in general more economically developed than ASEAN and is also more homogeneous in its level of development across its Member States than is the case across the 10 members of ASEAN. Although both have been widening over the years by accepting new members, this has added more to ASEAN’s overall diversity than it has the EU’s, further increasing the overall heterogeneity between the two groupings. Despite these differences, we believe that ASEAN and the EU share an essential similarity: they are both groupings of countries that recognise the importance of regional integration and the benefits of trade and investment in the context of a rules-based system. We therefore believe that putting the economic relations between the EU and ASEAN on the best possible footing is crucial to the long-term prosperity of ASEAN, as well as the EU.