Many Western countries face the challenge of reconciling future labor demand with growing public opposition to immigration. The dynamics and underlying processes of setting immigration requirements remain unclear as research so far mainly focuses on context-specific empirical studies. We use a public good game experiment with endogenous groups to investigate how different levels of perceived migrant potential and public debate shape immigration requirements. We employ the minimal group paradigm and immigration requirements are set by in-group voting. Our results suggest that fairness and efficiency of immigration requirements may best be described by the relationship between average population indicators and required contributions of immigrants. Public debate appears to foster fair and efficient requirements if perceived migrant potential is high.