In attempting to construct a comprehensive assessment of the impact of devolution on social policy in Scotland, Northern Ireland (NI) and Wales, making comparisons with England throughout, Derek Birrell employs a framework which works to group social policy developments across a range of sites into a ‘threefold typology of difference’ (p. 5), thus enabling the reader to negotiate his/her way through an extremely complex terrain. So, having examined the nature and extent of the devolution settlements in Scotland, Wales and NI, the centrality of social policy to each, the institutional differences across the nations and variations in the relationships between central bureaucracies, local government, quangos and arm's length public bodies in chapter 2, Birrell turns his attention to the categorising of policy developments. Here he identifies examples of: innovative policies introduced for the first time across the UK post-devolution (for example, the case of Children's Commissioners); policies that are distinctive in terms of being underpinned by the principle of universalism only since devolution (for example, the introduction of free personal and nursing care in Scotland); unique policy formations (for example, the emergence of distinct national policies relating to language); flagship policies as defined by the devolved administrations themselves (for example, student fees policy in Scotland); policy areas marked by significant divergence (focusing principally on differences in health and education policy across the four nations); and policies underpinned by shared basic principles across the nations, but where minor differences and incremental changes emerge at the level of implementation (for example, in the field of direct payments).

Where Birrell focuses on the issue of policy convergence in chapter 6, the main examples provided, perhaps unsurprisingly, are social security and tax credit policy as key ‘reserved’ areas. That said, the role of the EU, international conventions and intergovernmental organisations also feature in his discussion of ongoing convergence, along with a recognition of the significance of other factors and players in the shaping of social policy.

Another pleasing aspect of Birrell's work derives from his exploration of the interface between devolved and reserved powers. Here he highlights how the complex mix rarely makes for a clear-cut division of responsibilities between Westminster and the devolved administrations, but rather throws up a complicated reality in which devolved and reserved policy areas overlap or dovetail. Again the examples provided are illuminating insofar as they demonstrate the need for cooperation, communication and negotiation between different levels of governance. However, here I would have liked more discussion of the potential for conflict and paralysis, whereby resistance at one level, as a result of financial or ideological concerns for example, prevents progress at another. This kind of scenario can work to limit the potential for divergence in some cases, acting as an impediment to divergent policy aspirations especially where there is a different political party in power to that presiding over Westminster, and so deserves further exploration.

Assessing the effectiveness of the book as a whole, it is clear, as with all typological approaches, that there is scope to contest the placing of particular developments and question the necessarily artificial drawing of boundaries and positional judgements made by the author. Nevertheless, this represents an effective alternative to those narrower approaches that limit the comparison to England and one other nation within the UK and/or draw on a more manageable convergence–divergence dichotomy framework. What Birrell attempts to do is to strike a balance between providing a plethora of comparative policy detail and furnishing the reader with a sense of ‘the whole’ in terms of evidence in support of the idea that four systems of welfare are slowly emerging within the UK. Perhaps inevitably, the final result suffers from a lack of detailed policy analysis in places given the strong conclusions drawn at the end of some of the chapters, but then given the enormity of the task Birrell sets himself this is not a huge issue for a book of this type.

More important are the not insignificant limitations of chapters 8 and 9 in particular, which focus on the underpinning values and principles of post-devolution social policy across the four nations and a comparison of outcomes, respectively. Taking the outcomes chapter first, Birrell struggles to offer an interpretation of the data presented, not least given his inability to control for causal and/or contributory factors beyond the fact of devolution itself. This is a common problem when trying to assess the impact of policy, but one which limits the value of much of the data he displays. Better perhaps to focus on those potentially more illuminating statistics, which, for example, highlight the shifting balance of providers within the mixed economy of care home provision in Scotland since devolution in favour of private providers (p. 171). Such evidence suggests a gap between political rhetoric and welfare reality in Scotland, a theme that is not examined sufficiently in this book.

Finally, with regard to chapter 8 on values and principles, I felt that the author was not discerning enough on Scottish and Welsh differences in particular, suggesting something of a shared resistance to New Labour, certainly in the years before the election of the SNP in 2007. Here there is at least one misrepresentation of the arguments presented by other authors, in this case Mooney and Poole (2004), which leads the reader to question the reliability of the commentary more generally. Moreover, the conclusions presented in this chapter seem too sweeping, particularly regarding the rejection of market values in the face of the Private Finance Initiative (which Birrell acknowledges as a significant policy north and south of the border earlier in the book) and the various private sector inroads into the Scottish education sector, for example (albeit not as well developed or wide ranging as in England). Thus, for me, the analysis needed to be sharper and the summaries of the work of others more attentive, insightful and accurate for this book to hit all the right buttons.