Research Note Organized Labor Strikes and Social Spending in Latin America: The Synchronizing Effect of Mass Protest Dongkyu Kim Mi-son Kim Cesar Villegas ABSTRACT e theories and evidence about relationships between democracy and social spending in Latin America are highly contested. A recent study shows that collec- tive protest by organized labor effectively increases social security and welfare spending, whereas mass protest does not have comparable effects on human capital spending in Latin American democracies. is article reexamines the analysis and demonstrates that organized labor alone cannot sway democratic governments. Labor strikes require the synchronizing effect of mass protest to obtain government concessions. Only through concurrent episodes of mass protest can organized labor overcome the numerical disadvantage of pressing democratic government for social welfare spending. In understanding the relationship between labor protests and social welfare spending through the lens of insider-outsider dichotomy, it is critical to consider the synchronizing effect of mass protests. e findings remain robust with alternative measures of democracy and various model specifications. Keywords: Latin America, democracy, protests, social spending, organized labor T hat democracy increases social spending is a political science truism. As politi- cians in democracies try reaching a broader audience to stay in office, they pri- oritize spending items for the general public. In the context of Latin America, how- ever, recent econometric studies provide a complicated version of this truism. For one thing, evidence is mixed for social spending in general. While some studies find a positive effect of democracy, others fail to show any discernable effects (Brown and © 2020 University of Miami DOI 10.1017/lap.2019.62 Dongkyu Kim is an assistant professor of political science at the University of Texas Rio Grande Valley. dongkyu.kim@utrgv.edu. ORCID 0000-0002-3021-1912. Mi-son Kim is an assistant professor of political science at the University of Texas Rio Grande Valley. mison.kim@utrgv.edu. ORCID 0000-0002-2174-2041. Cesar Villegas is a graduate student in political science at the University of Rio Grande Valley. cesar.villegas01@utrgv.edu. ORCID 0000-0001-6982-783X. Conflict of interest: Dongkyu Kim, Mi-son Kim, and Cesar Villegas declare none.