We examine determinants of immigration requirements in a public goods game experiment with endogenous groups. Initially, the game consists of in-group players who enjoy an existing public good and out-group players who may subsequently enter the group. Motivated by different current migration flows and anti-immigration sentiments, our treatments are crafted to investigate how migrants' power of self-determination and public debate among in-group players shape immigration requirements. We employ the minimal group paradigm and immigration requirements are set by in-group voting. In order to immigrate, out-group players have to fulfill minimal contribution requirements. Public debate fosters coherence between the requirements and in-group players' contributions if migrants are free to reject requirements. Conversely, public debate among in-group players fosters economic exploitation of migrants with less bargaining power. Overall the study illustrates the novel potential of applying well-established tools from experimental economics to migration questions.