Although there has been significant improvement in employment and compensation in Mississippi since the mid-20th century, growth at the regional and national levels has been proportionately greater; consequently, in the early 21st century the state remained disadvantaged economically, with a per capita gross product that was among the lowest in the country. Manufacturing and services—primarily government (federal, state, and local), retail and wholesale trade, real estate, and health and social services—are the largest sectors of the state’s economy. The services sector has expanded particularly rapidly since the late 20th century.

Petroleum and natural gas account for the great bulk (in volume and in value) of all minerals produced in Mississippi. Important nonmetallic minerals include sand and gravel, fuller’s earth, and other clays. Iron has been mined intermittently since the late 19th century. Aluminum ores are low in quality, and they have been little exploited.

Most of Mississippi’s electrical power comes from plants fired by coal and natural gas and to a somewhat lesser extent from a nuclear power station near Port Gibson. Hydroelectric power in smaller amounts is brought into Mississippi from Tennessee Valley Authority dams and through interconnections with power companies in other states. A few private companies, numerous rural cooperatives, and several municipal generating systems are in operation.

In 1936 Mississippi adopted an industrial development program to “balance agriculture with industry,” and in 1965 the state’s industrial employment exceeded the number of agricultural workers for the first time. Manufacturing continued to expand until the end of the 20th century, when, following national trends, it began to decline. In the early 21st century, however, the sector remained an important contributor to the state’s gross product and a major source of employment. Mississippi’s principal manufactures include upholstered furniture, automotive parts, lumber and wood-related products (such as pulp and naval stores), and processed foods (especially seafood from the coastal waters). Pascagoula is the site of a major shipbuilding company.

Mississippi’s economy became less dependent on agriculture in the second half of the 20th century, and the number of farms and farm acreages declined significantly. By the early 21st century the sector represented only a tiny share of the state’s gross product and employed an even smaller segment of the population. Cotton, once king of Mississippi’s agricultural sector, now shares its reign with livestock, catfish from aquaculture, poultry, and various crops such as soybeans and sweet potatoes. The great majority of the state’s farms focus on livestock and dairy products, and Mississippi has become a leading producer of broiler chickens.

Mississippi, U.S.: cotton

Mississippi, U.S.: catfish farming

Lands in Mississippi that are unsuited to the cultivation of row crops are largely used for tree farms, orchards, or pastures. The state maintains an intensive reforestation program to replace the trees that are harvested each year as part of its forestry industry. Mississippi is one of the country’s top producers of lumber and wood-related products.

Mirroring the trend in many other states, the service sector in Mississippi has been on an upward swing since the late 20th century. A particularly notable development in the sector has been the expansion of casinos. In 1990 the Mississippi legislature legalized dockside casino gambling along the Gulf Coast and the Mississippi River. Casinos have since opened at various locations along the coast and in Natchez, Vicksburg, and Tunica county, which is one of the largest gaming markets in the United States. The Mississippi Band of Choctaw Indians also operates a casino on tribal lands near the town of Philadelphia.

The government is a major employer in Mississippi. Among the most prominent of the federal institutions is the John C. Stennis Space Center, located on the southern coast between Gulfport and New Orleans. It is one of NASA’s primary testing facilities for rockets—including the U.S. space shuttles.

Labour union membership in Mississippi is relatively small, although widely dispersed. Most large employers have a union membership. The state has a right-to-work law that prohibits compulsory union membership, however.

Mississippi’s major sources of revenue are sales taxes, followed by personal and corporate income taxes, gasoline taxes, and gaming income. Local governments derive their greatest income from property taxes. Considerable amounts of federal monies are provided through numerous federal and state agencies.

Rail transportation, a large segment of which is entirely intrastate, has generally declined since the late 20th century. However, the state’s secondary highway system has improved significantly. The heaviest volume of traffic is along the Gulf Coast, where numerous north–south and east–west routes converge.

Gulfport and Pascagoula can accommodate oceangoing ships, and low-draft oceangoing vessels can travel up the Mississippi River to Natchez, Vicksburg, and Greenville. Barge traffic moves on the Mississippi, Pearl, and Yazoo rivers. The Gulf Intracoastal Waterway passes through the Mississippi Sound along the Gulf Coast.

Mississippi has scores of public and private airports. Most large cities offer commercial service. There are international airports in the Jackson and Gulfport-Biloxi areas.