THE MARITIME SHIPPING SECTOR TRANSPORTS APPROXIMATELY 35% OF U.S. EXPORT VALUE AND 46% OF U.S. IMPORT VALUE. U.S. TRADE IN AGRICULTURAL PRODUCTS IS NEARLY TWICE AS DEPENDENT ON MARITIME SHIPPING AS IS OVERALL GOODS TRADE. THIS PROJECT SEEKS TO PROVIDE NEW AND NOVEL EMPIRICAL EVIDENCE ON SEVERAL QUESTIONS ABOUT THE ECONOMICS OF MARITIME SHIPPING. THE FIRST EMPIRICAL PAPER APPLIES A RECENTLY DEVELOPED ESTIMATION STRATEGY TO DECOMPOSE FREIGHT CHARGES INTO MARGINAL COSTS AND MARK-UPS. THE ESTIMATES CAN BE USED TO LINK THE ELIMINATION OF MARK-UPS TO INCREASED INTERNATIONAL TRADE FLOWS AND HIGHER U.S. WELFARE. A SECOND PROJECT APPLIES THE SAME ESTIMATING STRATEGY TO NEWLY IDENTIFIED DATA ON SHIPMENTS BETWEEN THE U.S. AND PUERTO RICO. COST AND MARK-UP ESTIMATES ON THESE SHIPMENTS ARE USEFUL BECAUSE THEY SHED NEW LIGHT ON THE ECONOMIC CONSEQUENCES OF A LONGSTANDING U.S. POLICY THAT PROHIBITS FOREIGN COMPETITION ON DOMESTIC SHIPPING ROUTES. A THIRD PROJECT DEVELOPS NEW THEORY AND BRINGS NOVELDATA TO BEAR IN ORDER TO STUDY THE ESTIMATE THE ECONOMIC BENEFITS LINKED TO HUB-AND-SPOKE ARRANGEMENTS IN INTERNATIONAL MARITIME SHIPPING. WE DEVELOP A METHOD FOR SEPARATELY VALUING HUBBING AND TRANSPORTATION SERVICES IN MARITIME SHIPPING, AND CALCULATE THE CONTRIBUTION OF HUBBING SERVICES TO ECONOMIC WELFARE IN THE DESTINATION MARKET. AMONG OTHER CONTRIBUTIONS, THE JOINT ANALYSIS OF HUBBING AND TRANSPORTATIONS SERVICES OFFERS NEW INSIGHTS INTO THE ECONOMICS OF INTERNATIONAL SUPPLY CHAINS.