To analyse tensions between fields, this presentation will focus on the work of two British organisations, Policy Exchange and the National Institute of Economic and Social Research, in the debates on the need for sharp fiscal consolidation after the 2008 financial crisis. While the first is a think tank closely linked to David Cameron’s Conservative Leadership, the second is a long-established institution specialised in the production of econometric forecasts and with several connections to academia and international organisations (such as the IMF). By analysing these think tanks' public interventions on macroeconomic policy between 2007 and 2013 and how their publics perceived them, this paper seeks to trace how these institutions sought to define what should be considered economically reasonable. It concludes by reflecting on a growing rift between the expert advice of those economic experts most closely linked to academia, and what is regarded more broadly as politically apposite and moderate.