After a decade of devolution and amid uncertainties about its effects, it is timely to assess and reflect upon the evidence and enduring meaning of any 'economic dividend' of devolution in the UK. Taking a multi-disciplinary approach utilising institutionalist and quantitative methods, this paper seeks to discern the nature and extent of any 'economic dividend' through a conceptual and empirical analysis of the relationships between spatial disparities, spatial economic policy and decentralisation. Situating the UK experience within the historical context of its evolving geographical political economy, we find: i) a varied and uneven nature of the relationships between regional disparities, spatial economic policy and decentralisation that change direction during specific time periods; ii) the role of national economic growth is pivotal in explaining spatial disparities and the nature and extent of their relationship with the particular forms of spatial economic policy and decentralisation deployed; and, iii) there is limited evidence that any 'economic dividend' of devolution has emerged but this remains difficult to discern because its likely effects are over-ridden by the role of national economic growth in decisively shaping the pattern of spatial disparities and in determining the scope and effects of spatial economic policy and decentralisation.