Thus, this essay will argue that ideas affect policy change only indirectly, as paradigms frames and determinants of interest, such that its importance in understanding policy change is only secondary to other approaches.
To better understand the importance of a study of ideas in policy change, it is first necessary to understand what ideas are. Ideas are shared beliefs held by individuals. However, a distinction must be made between two categories of shared beliefs, particularly "consensual beliefs" and "economic ideas", where although not mutually exclusive differ in their relation to policy. As Jacobsen explains, the difference lies between those of "means" to "ends", where consensual beliefs "shape the legitimate ends of economic activity"; economic ideas are the means to reach these ends. 3 Taking this definition of ideas, the importance of a study of ideas in policy change can be summarised in their roles as paradigms, roadmaps, or ideational frames.
Comparing policy change to scientific revolutions, Hall (1989) places emphasis on the role of ideas through "policy paradigms", or "roadmaps" as Goldstein and Keohane (1993) calls them, where ideas guide policies by determining the "tracks" of policymaking and setting constraints in the policy process4. As Hall argues, policy paradigms, determine policy change in acting as "a framework that specifies the goals of policy and the kind of instruments that can be used to attain them", as well as the "nature of the problems they are meant to be addressing."5 Campbell's (1998) and Beland's (2005) ideational frames or programmes also echoes Hall's concept of paradigms, varying only in the manner that ideas are presented and implemented in the policy process. Within this strand of literature, the failures of policies to achieve economic goals are seen as the impetus for policymakers to search for alternative ideas that pave the way for new policy paradigms to be accepted. Hence, in times of uncertainty marked with "exogenous shocks, demographic changes [or] the perception of failed policy", new ideas emerge as either roadmaps or focal points that reduce uncertainty and provide alternatives.6 The policy shift during the first Thatcher government can therefore be explained as the result of a shift in policy paradigms; replacing Keynesian ideas with monetarist ideas (Hall, 1993).
Looking at the first Thatcher government, it is evident that the policy shift coincided with an ideational shift from Keynesian to monetarist where Keynesian policies were perceived to have failed in resolving rising inflation (Walsh, 2000). In this respect,