Integration policy needs to be informed by evidence, but policy makers in the UK are not always able to turn to research to inform their decisions – even if their political masters allow them to do so. There are many reasons for this, and just two such reasons are that big administrative datasets are not analysed from the perspective of integration and there is a lack of longitudinal data about migrants’ integration trajectories. There are also many gaps in knowledge.

Looking at both quantitative and qualitative data, this chapter reviews research on integration. It starts by examining the different types of evidence and, in doing so, discusses the methodological challenges of researching integration. The chapter then looks at evidence from a thematic perspective, arguing that these studies neglect the social worlds of migrants. The chapter concludes with a discussion of how policy makers use research, and suggestions for improving the evidence base.

Sources of evidence

Alongside hundreds of quantitative datasets, there are thousands of academic articles, reports and books about migrant integration. These draw from different academic disciplines: sociology, anthropology, geography, social psychology, economics, social policy and political science. Reviewing this evidence requires categorisation, but such a sorting is difficult. The literature could be grouped thematically, into labour-market experiences, social relations and so on. Alternatively, research can be sorted conceptually, according to how authors understand integration. But it is worth starting with some methodological considerations and outlining the different types of evidence about integration, which can be broadly categorised as: (i) large datasets derived from the Census, surveys and administrative data, (ii) small-scale datasets, (iii) qualitative research and a small number of studies that have employed mixed methodologies and (iv) evaluations, ‘good practice’ literature and organisational information, for example, annual reports.

Large datasets

There is no UK dataset with a specific focus on migrant integration. Instead, researchers have to draw from other sources: the Census, large surveys and administrative data. What they choose to analyse will be determined by how researchers define integration.

The Census has included a country-of-birth question since 1841, which can be used to estimate the resident population of migrants (migrant stock).