Is Decentralization 'Glue' or 'Solvent' for National Unity?

The last two centuries have seen the rise of the nation-state as the dominant political institution around the world. However, “state” and “nation” are not always equivalent. In a surprising number of countries, autonomist and secessionist movements of varying strength and character remain active. The question we consider in this paper is whether decentralization is likely to hurt or help national unity in these “countries at risk.” After reviewing some of the relevant literature, we turn to the scanty empirical evidence supporting any view of this complex question, looking first at the very mixed stories of linkages between decentralization and national unity that emerge in a wide variety of countries around the world and then a bit more closely at the available time-series evidence in four OECD countries – Belgium, Spain, Canada, and the United Kingdom. The main conclusion that emerges from this review is essentially that as yet no one has either generally persuasive ideas or evidence about the impact of decentralization on national unity. In view of the complexity and context-sensitivity of the issue, this negative outcome is not surprising. In principle, decentralization may sometimes be a way station for a region on its way out of a country and in others an inducement for regions to stay rather than to leave. The impact of decentralization appears to depend not only upon the details of what is done but also the specific context and time when it is done, as well as at whose initiative