A number of scholars have shown how quantitative indicators and targets are performative, structuring knowledge about policy problems and even producing new forms governance. In this paper, we examine these processes in relation to the UK government's 2010 target of reducing net migration. We combine insights from two sets of literature: public policy theories of issue definition and framing; and STS ideas about stabilisation and performativity. Through an analysis of parliamentary and media coverage of the target, we distinguish two types of effect produced by the target: a framing effect, in terms of the technocratisation and compression – or ‘black-boxing’ – of debates on migration; and a political effect, whereby the government unleashed a self-reinforcing dynamic of political and media attention and scrutiny. We go on to explore how far these effects have influenced beliefs and expectations about appropriate governance of migration.
