It is always an honour to have Rudolf Klein engage with one's work. His review in this journal (Klein, Reference Klein2018) of my recent book is no exception. I am deeply gratified by his assessment of its scholarship and potential impact. I am moved to this rejoinder, however, because he and I differ on several points which I consider central to the purpose of the book: the dynamics of the opening of windows of opportunity for major policy change, the factors that drive decision-making within those windows and the importance of comparison across cases as an explanatory method.

The book presents a conceptual framework which responds to what I see as two key failings of the existing literature on policy change: an overly simple dichotomy between big-bang and incremental change, and the tautology of inferring a ‘window of opportunity’ from the fact that a burst of change occurred. First we need to understand when conditions are ripe for policy change – what opens ‘windows of opportunity’. But then we need to appreciate that there are two dimensions along which change can occur – scale and pace – yielding four strategies of change: big-bang (large scale, fast pace), blueprint (large scale, slow pace), mosaic (multiple small scale, fast pace) and incremental (small scale, slow pace). The choice among these strategies will turn first on whether or not the leaders of the winning coalition enjoy centralized control or must deal with other actors with independent power bases, and second on whether the various members of the coalition see their current positions of influence as precarious, stable or likely to improve. In the book's 10 cases in health policy across four countries and seven decades, we can observe these dynamics at work.

Windows of opportunity for major change in areas with large fiscal footprints and/or high public salience such as health care will open only when political leaders at the centre of government see a partisan advantage in taking the political risks entailed, and judge that they are in a sufficiently strong position both institutionally and electorally to build a coalition of support. One or another of these factors alone is insufficient incentive. I therefore disagree with Prof Klein that British institutional arrangements mean that ‘the window of opportunity is swinging open most of the time’. Simply having a majority government in a unitary system is not enough. As Prof Klein himself has written, the political risks of health policy change led Thatcher throughout her first two mandates to treat the NHS like an ‘unexploded bomb’. The two additional necessary conditions – an extraordinary electoral endorsement (as in a landslide or successive mandates) and a strong partisan imperative – did not come together for Thatcher until after the 1987 election, which gave Thatcher a third majority but which also heightened the salience of the NHS as a key Labour weapon.

My second concern is with Prof Klein's attribution to me of the view that big-bang change is the ‘norm’. This is emphatically not my view, and showing that four strategies are possible given a window of opportunity for change was a central motivation for me in writing the book. Blair's incrementalism is therefore puzzling at first blush not because big-bang change is the norm, or because incrementalism is somehow misguided, but because my argument would suggest that a strong majority government with a weakened opposition would have been poised for either a big-bang or a blueprint strategy, depending on how they saw their prospects for remaining in power past the next election. On closer examination, however, we observe the conditions that favour incrementalism – the need to negotiate the reform package among actors with independent power bases, at least some of whom judge that they will be in an improved position in the future and thus have an interest in agreeing to only such change as will give them a platform on which to build. Gordon Brown was in such a position in the Blair–Brown duopoly, and his tempering of proposals of larger-scale change by others in the government, including Alan Milburn, can be understood accordingly.

This last example brings me to my final concern – the importance of comparison in testing competing explanations for policy change. Prof Klein holds that distinctive features of British political institutions and policy design can explain the outcomes we observe. I fully accept the importance of institutional context and policy legacies: what is distinctive about national health care systems can be understood in those terms. What I seek to explain is rather the scale and pace at which those systems have (or have not) been transformed at various points. For that we need comparison and, I argue, an understanding of political incentives, which can be similar even in very different institutional contexts. Big-bangs have occurred in non-unitary systems like Canada and Australia. In Britain itself both ‘mosaic’ and incremental strategies have been adopted at times. Comparing the Blair/Brown episode with a Canadian case, in which Prime Minister Paul Martin also based an incremental strategy within a window of opportunity on the assumption that he would be in an even better position in the future, provides one example of cross-national similarity. Similarly, a comparison of the Obamacare reforms in the USA and those of the Coalition government in the UK reveals in each case a ‘mosaic’ strategy in which reforms had to be cobbled together from disparate pieces by actors with independent power bases, under time pressure, in the process of partisan deal-making within the executive and the legislature (albeit in somewhat different sequences). Broad patterns are also apparent: taking all 10 cases together we see that considerations of future prospects are not ‘redundant’: the expectation of future political advantage or disadvantage – what Jacobs (Reference Jacobs2011) would term ‘electoral safety’ – does vary over time and across nations, with predictable effects on the choice of strategies of scale and pace.

My interpretation of the cases in the book is based on extensive documentary and interview work regarding the motivations of central political actors and the options that they considered and chose. Nonetheless it is perhaps inevitable that in qualitative work such as this, differences of interpretation will arise. I am grateful to HEPL for this opportunity to clarify my work and, as always, to Rudolf Klein for his thoughtful and deeply informed commentary. It is my hope that the few, though key, differences between us will draw the attention of readers to the importance of understanding the strategic decisions that underlie policy change.