This article surveys the quantitative literature in coalition foreign policy. Tracing its development back to what we call the ‘first generation studies’ in Democratic Peace research, we illustrate that its theoretical and methodological foundations distinguish this literature from its predecessors. We then overview the existing studies along three dimensions: the nature of the dependent variables, the content of the key explanatory variables, and the processes that identify and systematise the institutional factors that influence coalition foreign policy. Our suggestions for future research highlight some of the puzzles motivated by the findings of this literature and the promise of multi-method designs.
