Urban and Rural (Population)
Urban and rural are type-of-area concepts rather than specific areas outlined on maps. As defined by the Census Bureau, the urban population comprises all persons living in urbanized areas (UA's) and in places of 2,500 or more inhabitants outside UA's.
The rural population consists of everyone else. Therefore, a rural classification need not imply farm residence or a sparsely settled area, since a small city or town is rural as long as it is outside a UA and has fewer than 2.500 inhabitants.The terms urban and rural are independent of metropolitan and nonmetropolitan designations; both urban and rural areas occur inside and outside SMSA's.
Except for the minor relaxation of UA criteria discussed below, urban and rural definitions have been consistent since 1950. Within small counties, measurements of urban and rural populations over time may he significantly affected by the increase or decrease of a place's population across the 2,500 population threshold, e.g., the increase of 1 person to a place of 2,499 results in an increase of 2,500 to the county's urban population.