This thesis provides a study of United Kingdom (UK) macroeconomic policy and economic ideas. Specifically, the thesis seeks to explore the reasons when and why UK macroeconomic policy and economic ideas exhibits change or continuity. The central contention of this thesis is that the model of punctuated equilibrium provides a flawed understanding and explanation of when and why policies and idea exhibit continuity and change in UK macroeconomic policymaking. In particular, the thesis seeks to fill two gaps in our existing knowledge of UK economic policymaking, which emerge from critical literature reviews. The first gap pertains to the need for greater specificity in our understanding and definition of orthodox UK macroeconomic policy. The second gap relates to the need for a superior understanding of when and why UK macroeconomic policy and economic ideas exhibits change and continuity. The original contribution of this thesis to the literature on UK economic policymaking arises from the two research findings generated in Chapters Three and Four, which are then tested in a series of case-study chapters in the second half of the thesis. The first research finding is the provision of greater precision in our understanding and definition of orthodox macroeconomic policy. The second research finding is the identification of a historical pattern in UK macroeconomic policymaking, which is named the orthodox cycle. The orthodox cycle utilises the new understanding and definition of orthodox macroeconomic policy to show the continuity of orthodox policy and ideas in UK macroeconomic policymaking, through a series of distinct phases, in the aftermath of crises and changes in government.