by William J. Mallett, Ph.D.
(Updated May 24, 2001)
Between 1947 and 1999, the public and private infrastructure capital stock of the United States more than tripled in real terms to stand at $7.4 trillion (in chained $1996 dollars). Calculating infrastructure in relation to the size of the population shows that the capital stock was worth about $26,600 per person in 1999, up from $13,800 per person in 1950. At the end of the 20th century, public infrastructure, including such things as roads, water and sewer facilities, and conservation and development structures, is a little less than two-thirds of the total infrastructure stock. That is higher than its share immediately after the second world war, but down from its peak in the late 1960s. Private infrastructure, including railroads, telecommunications, electric and gas utilities, and education and health services, makes up about one-third of the total stock.
The public infrastructure capital stock expanded greatly in the 1950s and 1960s, followed by much slower growth in the 1970s. Public infrastructure per capita, picked up again in the late 1990s, following a phase of moderate growth from the mid-1980s through the early-1990s. Private infrastructure growth per capita was negligible during the 1950s and 1960s boom on the public side, but picked up in the 1970s and 1980s. After dipping again in the early to mid-1990s, private side growth took off in the late-1990s.
The pattern of growth in the public infrastructure is largely a function of investment in streets, highways and education, which grew at a fast rate through the 1950s and 1960s with the building of the Interstate system and the baby boomers passing through the education system. Growth in the public street and highway infrastructure per capita began again in the mid to late 1980s, after reaching a plateau in the 1970s. Education infrastructure declined in the late 1970s through the mid-1980s with the baby bust generation, but picked up again the late 1980s. There has been steady growth in the per capital worth of other government buildings which includes general office and industrial buildings, police and fire stations, courthouses, auditoriums, garages, and passenger terminals.
Several elements of the private infrastructure stock – air transportation, telecommunications, and education and health services – have grown rapidly in the post World War II period. Since 1990, air transportation, trucking and warehousing, and other transportation services infrastructure have grown markedly. Telecommunications infrastructure also boomed in the 1990s with growth in the Internet and the cellular telephone industry. In per capita terms, the private electric utility infrastructure has declined from its peak in the late 1980s, a problem that coupled with increasing demand is beginning to affect power supply, most especially in California in 2001. Another potential area of trouble is in railroad infrastructure, which has declined steadily despite rising demand.