From the Introduction: "Puerto Rico's public debts, which totaled just over $70 billion when the Puerto Rico Oversight, Management, and Economic Stability Act (P.L. [Public Law] 114-187; PROMESA) became law on June 30, 2016, are now in the midst of one of the largest restructurings of public debt in U.S. history. Puerto Rico's fiscal troubles fell under national scrutiny during summer 2013, after the City of Detroit's bankruptcy filing reminded investors that municipal bonds are not risk free, and after the financial press noted the precarious state of Puerto Rico's public finances. Beyond the consequences for the island, likely to last decades, the restructuring of Puerto Rico's public debts could inform future federal responses to fiscal strains faced by some state and local governments. [...] This report outlines the accumulation of Puerto Rico's debt and the restructuring of the island's public debt through processes established by PROMESA. Puerto Rico's postwar economic development strategy of industrialization, as noted below, faltered after the 1973 energy crisis. Acute fiscal crises in 2006-2007 and 2013-2016 resulted in debt levels that could neither be sustained nor addressed through the Bankruptcy Code, which led to PROMESA's enactment. This report focuses on the largest portions of the island's public debt."
CRS Report for Congress, R46788
Congressional Research Service: https://crsreports.congress.gov/