Census data are available for a number of different geographic
units. Community areas. Community areas, of which there are 77
in Chicago, are supposed to be homogenous neighborhood-like
districts. Many, but not all, do in fact correspond quite
closely to neighborhoods that would be recognized by their
residents; examples of these are Hyde Park and Uptown. Community
areas are peculiar to Chicago. They were apparently first
proposed by members of the Social Science Research Committee at
the University of Chicago during the 1920s. They have been used
ever since by the city government as statistical units. They
have the virtue of consistency; except for the addition of
O'Hare and the splitting of Edgewater from Uptown, they have
remained unchanged since their inception. The U.S. Census Bureau
does not compile data for community areas. Although most
community area boundaries are coincident with census tract
boundaries, because the city limits intersect census tract
boundaries in several places, it is not possible