This document discusses the benefits of multi-level governance and provides examples from OECD countries. It finds that devolving spending to lower levels of government is common among OECD nations. Subnational governments play a key role in many policy areas. The document also examines reforms to improve coordination across different levels of government to maximize public investment. It proposes that the OECD provide guidance, tools, and support to strengthen capacities for decision-makers implementing macro-regional strategies like the EU Strategy for the Adriatic and Ionian Region.