This study explores the effectiveness of Get Out The Vote (GOTV) interventions during Brazil's largest participatory budgeting vote.

Context & Background: Participatory Budgeting represents a unique form of democratic engagement in Latin America, particularly prominent in Brazilian cities. However, translating this local phenomenon to national-level significance remains under-explored.

Methodology & Data Source: The research utilizes an experimental design conducted during the 2016 municipal elections across selected precincts in three major Brazilian states (Rio Grande do Sul, Bahia, and Rio de Janeiro). These were chosen for their varying levels of political engagement but all featured active participatory budgeting platforms.

Key Findings: Contrary to conventional polling wisdom that large-scale electoral events naturally attract voters, this experiment reveals targeted GOTV messaging significantly increased turnout. Even small interventions tailored explicitly to PB participants could shift voting behaviors on a national scale during Brazil's largest ever PB event.

Implications for Political Science Research: This suggests novel pathways exist for civic mobilization beyond traditional campaign strategies or established political infrastructure. The findings provide crucial insights into the mechanics of democratic participation and offer practical guidance for designing effective engagement strategies at large scales, even in non-election periods.