The changingprofile of a city in the UnitedStates is apparent in the shiftingdefinitionsused by the UnitedStatesBureau of the Census. In 1870 the censusofficiallydistinguished the nation's "urban" from its "rural" population for the firsttime. "Urbanpopulation" was defined as personsliving in towns of 8,000 inhabitants or more. But after 1900 it meantpersonsliving in incorporatedplaceshaving 2,500 or moreinhabitants.
Then, in 1950 the CensusBureauradicallychanged its definition of "urban" to takeaccount of the new vagueness of cityboundaries. In addition to personsliving in incorporatedunits of 2,500 or more, the census now includedthose who lived in unincorporatedunits of thatsize, and also all personsliving in the denselysettledurbanfringe, includingbothincorporated and unincorporatedareaslocatedaroundcities of 50,000 inhabitants or more. Eachsuchunit, conceived as an integratedeconomic and socialunitwith a largepopulationnucleus, was named a StandardMetropolitanStatisticalArea (SMSA).
EachSMSAwouldcontain at least (a) one centralcitywith 50,000 inhabitants or more or (b) two citieshavingsharedboundaries and constituting, for generaleconomic and socialpurposes, a singlecommunitywith a combinedpopulation of at least 50,000, the smaller of whichmusthave a population of at least 15,000. Such an areaincluded the county in which the centralcity is located, and adjacentcountiesthat are found to be metropolitan in character and economically and sociallyintegratedwith the country of the centralcity. By 1970, about two-thirds of the population of the UnitedStates was living in theseurbanizedareas, and of thatfiguremorethanhalfwerelivingoutside the centralcities.
While the CensusBureau and the UnitedStatesgovernmentused the termSMSA (by 1969 therewere 233 of them), socialscientistswerealsousing new terms to describe the elusive, vaguelydefinedareasreaching out fromwhatused to be simple "town" and "cities". A host of termscameinto use: "metropolitanregions", "polynucleatedpopulationgroups", "conurbations", "metropolitanclusters", "megalopolises", and so on.
【題組】47. Which of the following is NOT true of an SMSA?
(A) It has a population of at least 50,000
(B) It can include a city's outlyingregions (C) It can includeunincorporatedregions (D) It consists of at least two cities.