AbstractThe decentralization of the State’s powers, through the Puerto Rico Autonomous Municipalities Act (Act N° 81, 1991), had the purpose of provide greater power to the 78 municipalities of the island for their economic and social improvement. This decentralization brought its challenges and evidenced differences in administrative capacities and human and fiscal resources. In response to these challenges, municipal consortiums have been a mechanism to address the lack of capacity in various areas, such as administrative, human resources and budgetary. They have also been one of the mechanisms developed with the main purpose of promoting local development and responding in an innovative way to problems that impact citizens, such as the fragility of the energy service and the access to water. Using secondary sources generated by consortia, government offices and local newspapers, this exploratory study aims to examine the socioeconomic impact of municipal consortia in Puerto Rico. It enquires into the premises for the creation of consortia (alliances) in Puerto Rico since the 1980s, such as labor development, local development and sustainable development. It also identifies the results, challenges and benefits they have experienced. Finally, it evaluates their capacities using the results of the administrative audits conducted by the Office of the Comptroller of Puerto Rico. Although it cannot be categorically concluded that the consortia have promoted the local development of the municipalities, the collaborative and innovative work has allowed them to be more effective in addressing some critical problems of citizens. From the 78 municipalities, 69 participate in five consortia focused on economic development. The data reveals that the nine municipalities without participation have had the greatest population loss. In addition, while per capita income increased in both consortia and non-consortia municipalities, the largest increase occurred in the municipalities clustered in three of the five existing consortia.