Most accounts of states and knowledge see knowledge as crucial to realising state governing projects and for underpinning the ‘epistemic authority’ of the state. This chapter questions the underlying assumptions these accounts make about state motivation or rationality. Building on theories of state legitimation, it argues that we should see knowledge production as highly selective and contingent. The chapter then elaborates on the three lenses for exploring ignorance: (a) omission, inspired by theories of bounded rationality and information processing; (b) strategy, building on sociological and anthropological notions of strategic ignorance and (c) ascription, building on theories of social movements and focusing on processes of claims-making and political contestation that expose state ignorance.

This chapter explores the asylum crisis of the 1990s. We examine how officials in Germany and the UK dealt with growing evidence of a sizeable population of irregular migrants by deploying the three main strategies for responding to ignorance: denial, elucidation and resignation. Although both governments pursued forms of denial and resignation, these took different forms. In the UK, pragmatism about the limitations of state capacity implied that officials were sanguine about their ‘ignorance’, with pressure emanating from external political scrutiny. In Germany, officials faced an acute conflict between bureaucratic and legal norms of the rule of law. Both cases reveal profound state ambivalence about elucidating a social problem over which they had limited control.

This chapter charts how irregular migration was first identified in France and the UK as a social problem requiring state intervention. Building on theories of information processing, it explores the filters through which each government scanned their political and operational environment to identify and frame the issue. In the UK, a political preoccupation with limiting overall numbers of Commonwealth migrants led to measures to penalise ‘evasion of control’ in the late 1960s. In France, concerns about 'clandestine work' prompted a focus on irregular labour in 1970s, which built on earlier security priorities tied to the Algerian War. By locating the emergence of the issue in historical and cross-national context, our analysis highlights the contingent and selective nature of state knowledge production about irregular migration.

This introductory chapter sets out the core arguments of the book. It introduces the key concepts and theoretical approach, including state rationality, strategies of knowledge production and state ignorance. It then outlines the three lenses for exploring ignorance: ignorance as omission, ignorance as strategy and ignorance as ascription. Finally, it sets the scene for the empirical analysis, introducing the issue of irregular migrants, and explaining the comparative research design that focuses on three case studies: France, Germany and the UK.

In our concluding chapter, we review the evolution of state infrastructures of control. Such infrastructures embody state beliefs about how best to steer migrants, and also provide maps with which states ‘see’ their unauthorised populations. We chart changes in infrastructures since the 1960s across three dimensions: styles, sites and temporalities of control. The analysis highlights the continued reliance on centralised command and control approaches in Germany, despite niggling concerns that they are not capturing the full picture. In France, patchy implementation of work and welfare restrictions, and a sharp left-right divide on the issue, has repeatedly led governments back to the tool of regularisation. In the UK, lack of internal control infrastructure has been compensated for by outsourcing to external organisations, meaning that migrants get ‘caught’ at later stages in their lives when they are most reliant on social and economic support. We explore the implications of these different infrastructures on state knowledge and ignorance.

The 1980s and 1990s saw a phase of increasing intergovernmental cooperation between European countries, culminating in Schengen and EU cooperation on immigration. This sharply exposed the divergence of migration control across European countries, triggering both ‘learning effects’ as countries adapted domestic legislation on asylum and borders, and ‘compensatory effects’ to mitigate the loss of internal Schengen border controls. Yet rather than leading to convergence, national systems of internal migration control remained surprisingly enduring. The chapter shows how the persistence of these divergences made arrangements on Schengen and free movement vulnerable to political shocks such as the 2015 refugee crisis and Brexit.