Most recent research about democratic innovations has neglected the analysis of one of the most widespread participatory institutions: associationally based institutions that exist and meet regularly at the neighborhood or policy level. Fung (2004) claimed the crucial role that the “accountable autonomy” of these institutions could have, but limited research has been developed around other similar but probably less successful cases. Our research aims to map these associational institutions in Spain using a multilevel perspective, covering from the national level to the local (cities of more than 200.000 inhabitants). The paper will discuss how to measure their performance and three main explanations of their different performance (diversity of associational representation and role of political conflict and institutional design).