This paper explores empirically the role of nomination procedures on political selection and the determinants for adopting contestable selection methods such as primaries. Using data from Latin American parties, I find evidence that political competition increases probability of primary adoption. Moreover, primary nominated candidates obtained larger vote shares and during their mandate countries experienced improvements in several measures of quality of government. The results exploit within party variation and are robust to relevant identification concerns. Together, these findings suggest that nomination procedures matter for political selection and that the quality differences are significant enough to influence electoral and economic outcomes.