Local councils in Latin America often fail to hold mayors accountable, even where they are legally required and empowered to do so. These failures are particularly significant, considering that decentralization has given greater power to mayors throughout the region. The dissertation aims to improve our understanding of local horizontal accountability by analyzing the influence of mayors and constituencies on local councils’ disposition for horizontal accountability, and by conceiving these actors as embedded in systems of local relationships. Following an inductive and theory building strategy, the research compares five municipalities in Santiago de Chile with diverse socioeconomic and political features using original qualitative evidence.

The results challenge explanations of accountability based on administrative capacity, socioeconomic characteristics, and partisan alignments. They show, instead, that the configuration of local systems of relationships—comprising relationships between councils, executives (i.e., the mayor and the municipal bureaucracy) and constituencies (i.e., the local voters)—have significant effects over a critical factor determining Municipal Councils’ disposition for horizontal accountability: their autonomy from the mayor.

According to the cases analyzed, local councils’ dependence on the mayor is a significant factor for inhibiting their disposition to hold these mayors accountable. This dependence has a critical electoral component, thus making the triangular relations between council members, local executives and constituencies a determinant factor going beyond their party affiliation. Specifically, and as a general proposition, when council members are unable to generate and maintain sufficient constituent support, local executives can use their resources and influence to reduce or increase council members’ electoral chances. This influence on council members’ electoral performance can be used to induce their loyalty to the mayors, thus discouraging them from holding these mayors accountable.

Constituencies, therefore, also play a significant role in local horizontal accountability, by giving council members a chance to be autonomous from their mayors despite their disposition to hold the mayor accountable (or lack thereof). This autonomy, however, disappears if council members rely on the help of the local executives to obtain constituents’ support.