The EU and its Member States pursue a wide range of policies that address migration, including development cooperation, border management, and legal labour market access. To be effective, policies must be based on an accurate understanding of how individuals decide whether to migrate. DYNAMIG will fill critical gaps in scientific and policymakers’ knowledge about how the decision-making behaviour of potential and actual migrants interacts with policies given micro, meso, and macro factors, e.g. different socioeconomic status. We focus on Africa as the most important future region of origin for migrants to Europe. We pursue a multi-disciplinary approach along four dimensions: First, we extend existing conceptualisations of the dynamics of migration decisions along extended trajectories and test these through innovative methods, including digital diaries collected from migrants en route from Nigeria, Kenya, Senegal, and Morocco to Europe. Second, we develop a mobile-device-based tool for online choice experiments to causally study aspiration formation across different contexts and stages of migration with several tens of thousands of individuals in origin and transit countries. Third, we study how policies affect migration decision-making with methods that allow causal interpretation: choice experiments with respondents in different contexts; a randomised controlled trial of an entrepreneurship training intervention in Senegal; and a quasi-experimental analysis of the EUTF for Africa. Fourth, through interviews with high-level policymakers and textual analysis of policy documents, we analyse how the design of EU, Member State, and relevant African policies that address migration takes into account migrant decision-making. To maximise our impact on policymaking, we embed our research in an intentional process of joint knowledge creation with stakeholders in Europe and Africa, including the policymaking community, migrant and diaspora organisations, and civil society.