Economy. The U.S. Virgin Islands economy is based primarily on tourism and other services. The leading sectors in employment are government service; trade, encompassing personal, business, and domestic services including tourism; manufacturing; and finance, real estate, and insurance. The Economy in the U.S. Virgin Islands; Tourism is the primary economic activity, accounting for 80% of GDP and One of the world's largest petroleum refineries is at Saint Croix. Agriculture: 1%; Industry: 19%; Services: 80% ( est.).