Between 1945 and 2005, the United Kingdom underwent two deep-seated institutional transformations—roughly starting around 1945 and 1979 respectively—when all received wisdom on how to govern the economy was called into question and the basic terms of the political debate were changed. Attlee and Thatcher emerge as the great "innovators" who were able to effectively implement most of their political platforms. During those two time intervals (1945-1979 and 1979-2005), there were also two opportunities to challenge the prevailing institutional arrangements. Heath won the general election in 1970 promising a radical overhaul of Britain's institutions, only to fail in 1972, when he was forced to take a U-turn; and Blair's "New Labour," winning a larger majority in 1997 than Labour in 1945, did not accomplish a major break with the Thatcherite settlement but ended up strengthening it instead.

The dissertation attempts to answer this puzzle by considering the impact of economic crisis on bringing about policy change, through an intertemporal and qualitative comparison of four case studies: 1945-51 (Attlee), 1970-74 (Heath), 1979-90 (Thatcher), and 1997-05 (Blair). The central argument of the dissertation is that the key to continuity and change in economic policymaking is the role that available ideas play during periods of sharp economic downturns in defining the various options of government policy. When economic turmoil is perceived both by the general electorate and constructed by the political establishment as a real "crisis," then new ideas will matter if they offer an explanation of what went wrong, and how it call be fixed, and subsequently can function as a roadmap for an emerging new institutional structure. If there is, however, no real perception of crisis, then there will be little incentive for radical transformations, and institutional change will at most be incremental. In the latter case, new ideas will play a marginal role and will only be implemented insofar as they 'fit' into the existing settlement, leading to a path dependent future institutional development. Instead of changing the status quo, these changes will end up strengthening the current institutions by eliminating their minor weaknesses, making future reform more difficult.