This project uses a mixed methods design to assess the role of political deliberation in expansionary social policy reforms of the 20th century. Normative political theory requires that politicians justify their reform proposals for a democratic order to be considered legitimate and these practices of justification arguably lead to consensus-oriented outcomes supported by a broader public. The role of deliberation in social policy reforms remains unclear for two main reasons. First, existing scholarship tends to read preferences off of socio-economic position rather than assess how preferences form dynamically, not least during reform process. Also, some institutions that promote deliberation are related to more generous social policy, which one might expect if deliberation leads to more inclusive outcomes. However, other institutions that nurture deliberation are actually related to less generous social policy outcomes, raising questions about whether deliberation facilitates or hinders welfare state development. This project first uses linear regression to analyze a new dataset of social policy reforms for 16 countries between about 1900 and 1980 to assess how reforms vary by government type, institutional context, etc. Then a second part uses qualitative and quantitative content analysis to analyze political deliberation over a subset of reforms, which are embedded in country case studies that include information on the country’s social, political, and economic context.