Lobbying coalitions and their determinants: a systematic literature review

Abstract This article provides a systematic literature review of the scholarly work on lobbying coalitions in political science, spanning the period from 1985 to 2023. By applying the PRISMA protocol for scoping reviews, the study maps the key trends, definitions adopted, research methods, and theoretical frameworks within this field, specifically focusing on the main explanations used to account for interest groups’ choice to form or join a coalition. The review reveals that the study of lobbying coalitions has grown in prominence, with a prevailing focus on the United States and the European Union and with a predominant use of large-N quantitative methods. The review identifies the dominance of behavioral definitions of interest groups and lobbying coalitions while also highlighting significant methodological gaps, particularly the underuse of social network analysis and qualitative comparative analysis. Furthermore, the study presents a meta-analysis of theoretical hypotheses, showing that the decision to form or join coalitions is primarily influenced by micro- and meso-level factors such as ideological affinity and issue salience. The review finds mixed empirical support for the idea that coalition formation serves as a ‘weapon of the weak’, with both weaker and stronger groups demonstrating likelihood of joining coalitions under certain conditions. The paper concludes by suggesting avenues for future research, including the further exploration of mixed-method designs and the potential for alternative methodological approaches to refine the understanding of lobbying coalitions.