To contribute to the debate about the reorganization of public-school supply, we analyze a reform introduced in Colombia in 2001 that merged independent schools into a single institution. Specifically, we estimate differences in achievement, dropout rates, teacher characteristics, and technological infrastructure between sites belonging to multi-site schools and single-site schools. Our results suggest that there are no differences in test scores, but lower dropout rates in multi-site schools. Also, we found that sites belonging to multi-site schools, especially in larger networks (more than six sites) and far away from the main site of the school, have younger teachers with lower salaries who are more likely to have a temporary contract. Finally, we provide suggestive evidence that more isolated sites from large-sized schools have less access to the internet and a computer room than single-site schools. These results provide evidence for reforms to increase cooperation between sites.