According to the United Nations’ International Migration Report, there were an estimated 258 million international migrants living abroad in 20171. Meanwhile, high-profile restrictions and heated rhetoric have dominated media coverage of immigration. From the United States’ ‘Muslim ban’2,3 and proposed end to family reunification visas4 to the United Kingdom’s talk of a £30,000 salary requirement for all new high-skilled migrants5, the current discussion of immigration seems dominated by restrictions and uncertainty.

Much of the international conversation on immigration has focused on questions of policy. Are countries in the Global North currently doing enough to fulfil their obligations under international law to provide asylum for those who flee persecution? Should there be limits on the admittance of economic migrants? Should certain categories of immigration be encouraged or permitted above others? How can governments promote the integration and success of new arrivals? In the midst of these policy debates, it is sometimes easy to lose track of the fact that individual-level decisions are a fundamental component of immigration outcomes. People move abroad for a host of individual reasons, from the tragic to the exciting. The decisions to stay or return, and how to go about building a new home, are equally personal.

A study by Michael Hotard and colleagues published in this issue of Nature Human Behaviour highlights the importance of understanding key individual-level decisions about migration and removing barriers that could prevent people from acting on the choices that they would prefer to make6. The authors conducted a trial in 2017 in which New York residents who were eligible for federal fee waivers to cover the cost of application for United States citizenship were either provided with general information about the process and referral to further assistance or were also explicitly told that they were likely eligible for a fee waiver (all participants were later informed of their eligibility). In the 4–8 months following the intervention, rates of application for citizenship were higher among those who were informed of their waiver eligibility.

The study suggests that people who would choose to naturalize, thus gaining greater legal protections, employment opportunities and political rights, are often deterred because they are not aware that assistance exists to make it a financially viable option. Even if a policy exists that should promote naturalization, the expected outcome might not emerge because individuals face barriers that shape their decisions in unexpected ways. Policies affect immigration, but a focus on how people act in response to policy options and the choices they make is still an essential part of understanding immigration patterns and outcomes.

A key feature of decisions at the individual level is that they often do not line up with government incentives or preferences. While it benefits immigrants to learn that they can apply for citizenship at no cost, it is quite likely the current United States administration would prefer not to increase rates of fee waiver use. Whether any study of immigration has a direct impact on policy depends on the priorities of the governments who would act on the results. Yet even if policies don’t immediately change, studies that explore the ways in which they could are critical for furthering our understanding of immigration. This sort of policy-relevant research provides important information about responses to immigration policies and programs that is valuable for policymakers, advocacy groups and immigrants, even if the immediate impact on national policy is not straightforward.

This information is especially important in contexts where national governments do not exercise sole control over policies and programs that affect immigration. The fee waiver trial reported in this issue took place in New York as part of a larger state-level program designed to reduce barriers to naturalization that was operated as a partnership by both state agencies and community organizations. However, the intervention in the study involved informing people of their eligibility for federal waivers, rather than distributing local funds. The study mechanics show how the impacts of national policies can also be shaped by the actions of lower-level authorities and private foundations. Understanding how people make decisions in the context of particular policy environments can therefore be important information for a wide range of audiences.

Furthermore, knowing how people engage with existing resources provides valuable information about how and why people make major immigration decisions. By focusing on individual-level decisions, the study offers insight into the immigrant experience. The authors show an important aspect of how people make a key decision about immigration and how this decision might be different under even slightly changed circumstances.

This focus on how people experience and make decisions about international movement offers a look at the human side of immigration. Policy matters, but it is essential to remember that people live these policies every day, and policy alone is sometimes not enough to determine outcomes. Consideration of the individual immigrant experience is therefore a critical part of conversations and research about immigration.