“Comparing implementation practices across national and sub-national contexts: advantages and challenges”

Starting from two comparative research projects on the implementation of nationality and citizenship policies, we explore the challenges and advantages of doing comparative research on the implementation of nationality and migration laws. We have conducted in particular ethnographic research on the implementation of various citizenship policies (naturalisation, citizenship revocation) in the UK and France (Fargues) and UK and Belgium (Sredanovic). Comparative work in this field is subject to traditional challenges that any comparative research design involves (e.g. issues of comparability across cases, choice of large-N vs. small-N research designs, choice of methodologies, etc.). It is also subject to more specific challenges, including the variation in centralised and decentralised procedures, in the number and kind (public/private, specialised/non specialised) institutions involved, and in the level of discretion and judicial review available. Further, the availability of data depends on the degree of motivation required in the decision (and in the presence of informal rejection of applications), the percentage of rejected application that are appealed in court, and the degree to which institutions compile and make publicly accessible statistical data about the outcomes. Depending on such factors, the data available on the implementation of policies can be more or less opaque (e.g. in relation to the motivations of the decisions) and more or less accurate (e.g. in terms of ratio of acceptance/refusals). At the same time, comparative work allows to avoid pitfalls such as overgeneralisation of the results and overspecificity of the explanatory models, and allows to trace the diffusion and local adaptations of specific policies across different countries and across the sub-national institutions involved in implementation. Building on our own experiences as researchers on the implementation of nationality and migration laws and engaging with other studies on the same topic, the main ambitions of this paper will be (1) to discuss various obstacles that researchers in this area are likely to face and imagine ways in which they might be able to circumvent those difficulties; (2) delineate key contributions that comparative research on implementation practices is likely to make, provided that the difficulties identified can be successfully addressed.