 This paper investigates the potential of Web 2.0 technologies as new data sources for social policy analysis, specifically using Twitter data to derive indications of active citizenship, a dimension of social capital. The study compares official survey results with findings from an analysis of Twitter data and finds that both methods have their own strengths and weaknesses, best results may be achieved by the combination of both. Official surveys are statistically robust and representative, while Twitter data offer more timely and less costly information with higher spatial and temporal resolution. The research presents a full methodological workflow for analyzing and comparing these two data sources, advancing the debate on how social media data can be mined for policy analysis. This article was authored by Christina Rosolis Sanchez, Massimo Cralia, and Arnold K. Brecht.