Do political outcomes respond more strongly to the preferences of the rich? In an age of rising inequality, this question has become increasingly salient. Yet, although an influential literature has emerged, no systematic account exists either of the severity of differentials in political responsiveness, the potential drivers of those differentials, or the variation across democracies. This article fills that gap. We analyze 1,163 estimates of responsiveness from 25 studies and find that, although this research collectively suggests that political outcomes better reflect the preferences of the rich, results vary considerably across models and studies. The divergence in results is partly driven by partisanship and the model specification, while we find no significant variation across either policy domains or general/specific measures of political outcomes. Finally, and against theoretical expectations, published research suggests that differentials in responsiveness are weaker in the United States compared to other developed democracies. The article contributes to our understanding of differential responsiveness by clarifying the main debates and findings in the literature, identifying issues and gaps, and pointing to fruitful avenues for future research.