Section 27 of the Merchant Marine Act of 1920, commonly known as the Jones Act, requires that all goods transported by water between US ports be carried on ships built, owned, and flagged in the United States, and crewed by US citizens. Enacted shortly after World War I to maintain a robust domestic merchant marine capable of supporting national defense, the law successfully created a protected national maritime infrastructure. However, for non-contiguous US territories like Puerto Rico, Hawaii, and Alaska, the statute has generated severe long-term economic consequences.
Because US-built and crewed vessels are vastly more expensive to operate than foreign-flagged alternatives, shipping costs to Puerto Rico are drastically inflated. Importers must pay significantly higher rates to bring basic necessities, energy supplies, and food from the US mainland, passing those expenses directly onto local consumers. When natural disasters like Hurricane Maria strike the island, the Jones Act complicates relief efforts by preventing foreign ships from delivering emergency supplies directly from US mainland ports without explicit emergency waivers.
Economists estimate the law costs Puerto Rico hundreds of millions of dollars annually, sparking ongoing debates between maritime labor advocates who champion national security and critics who demand statutory reform.