In the United States during the 1940s, for the first time a powerful interaction between segregation laws and race differences in terms of socioeconomic status enabled white families to abandon inner cities in favor of suburban living. The result was severe urban decay that, by the 1960s, resulted in crumbling "ghettos". Prior to national data available in the 1950 US census, a migration pattern of disproportionate numbers of whites moving from cities to suburban communities was easily dismissed as merely anecdotal. Because American urban populations were still substantially growing, a relative decrease in one racial or ethnic component eluded scientific proof to the satisfaction of policy makers. In essence, data on urban population change had not been separated into what are now familiarly identified its "components." The first data set potentially capable of proving "white flight" was the 1950 census. But original processing of this data, on older-style tabulation machines by the US Census Bureau, failed to attain any approved level of statistical proof. It was rigorous reprocessing of the same raw data on a UNIVAC I, led by Donald J. Bogue of the Scripps Foundation and Emerson Seim of the University of Chicago, that scientifically established the reality of white flight.
It was not simply a more powerful calculating instrument that placed the reality of white flight beyond a high hurdle of proof seemingly required for policy makers to consider taking action. Also instrumental were new statistical methods developed by Emerson Seim for disentangling deceptive counter-effects that had resulted when numerous cities reacted to departures of a wealthier tax base by annexation. In other words, central cities had been bringing back their new suburbs, such that families that had departed from inner cities were not even being counted as having moved from the cities.
During the later 20th century, industrial restructuring led to major losses of jobs, leaving formerly middle-class working populations suffering poverty, with some unable to move away and seek employment elsewhere. Real estate prices often fall in areas of economic erosion, allowing persons with lower income to establish homes in such areas. Since the 1960s and changed immigration laws, the United States has received immigrants from Mexico, Central and South America, Asia, and Africa. Immigration has changed the demographics of both cities and suburbs, and the US has become a largely suburban nation, with the suburbs becoming more diverse. In addition, Latinos, the fastest growing minority group in the US, began to migrate away from traditional entry cities and to cities in the Southwest, such as Phoenix and Tucson. In 2006, the increased number of Latinos had made whites a minority group in some western cities.
In the 1930s, states outside the South (where racial segregation was legal) practiced unofficial segregation via exclusionary covenants in title deeds and real estate neighborhood redlining – explicit, legally sanctioned racial discrimination in real property ownership and lending practices. Blacks were effectively barred from pursuing homeownership, even when they were able to afford it. Suburban expansion was reserved for middle-class and working-class white people, facilitated by their increased wages incurred by the war effort and by subsequent federally guaranteed mortgages (VA, FHA, HOLC) available only to whites to buy new houses, such as those created by the Federal Housing Administration.
After World War II, aided by the construction of the Interstate Highway System, many White Americans began leaving industrial cities for new housing in suburbs. The roads served to transport suburbanites to their city jobs, facilitating the development of suburbs, and shifting the tax base away from the city. This may have exacerbated urban decay. In some cases, such as in the Southern United States, local governments used highway road constructions to deliberately divide and isolate black neighborhoods from goods and services, often within industrial corridors. In Birmingham, Alabama, the local government used the highway system to perpetuate the racial residence-boundaries the city established with a 1926 racial zoning law. Constructing interstate highways through majority-black neighborhoods eventually reduced the populations to the poorest proportion of people financially unable to leave their destroyed community.
The real estate business practice of "blockbusting" was a for-profit catalyst for white flight, and a means to control non-white migration. By subterfuge, real estate agents would facilitate black people buying a house in a white neighborhood, either by buying the house themselves, or via a white proxy buyer, and then re-selling it to the black family. The remaining white inhabitants (alarmed by real estate agents and the local news media), fearing devalued residential property, would quickly sell, usually at a loss. The realtors profited from these en masse sales and the ability to resell to the incoming black families, through arbitrage and the sales commissions from both groups. By such tactics, the racial composition of a neighborhood population was often changed completely in a few years.
Association with urban decay
Urban decay in the US: the South Bronx, New York City, was exemplar of the federal and local government's abandonment of the cities in the 1970s and 1980s; the Spanish sign reads "FALSAS PROMESAS", the English sign reads "BROKEN PROMISES".
Urban decay is the sociological process whereby a city, or part of a city, falls into disrepair and decrepitude. Its characteristics are depopulation, economic restructuring, abandoned buildings, high local unemployment (and thus poverty), fragmented families, political disenfranchisement, crime, and a desolate, inhospitable city landscape. White flight contributed to the draining of cities' tax bases when middle-class people left. Abandoned properties attracted criminals and street gangs, contributing to crime.
In the 1970s and 1980s, urban decay was associated with Western cities, especially in North America and parts of Europe. In that time, major structural changes in global economies, transportation, and government policy created the economic, then social, conditions resulting in urban decay.
White flight in North America started to reverse in the 1990s, when the rich suburbanites returned to cities, gentrifying the decayed urban neighborhoods.
Government-aided white flight
New municipalities were established beyond the abandoned city's jurisdiction to avoid the legacy costs of maintaining city infrastructures; instead new governments spent taxes to establish suburban infrastructures. The federal government contributed to white flight and the early decay of non-white city neighborhoods by withholding maintenance capital mortgages, thus making it difficult for the communities to either retain or attract middle-class residents.
The new suburban communities limited the emigration of poor and non-white residents from the city by restrictive zoning; thus, few lower-middle-class people could afford a house in the suburbs. Many all-white suburbs were eventually annexed to the cities their residents had left. For instance, Milwaukee, Wisconsin partially annexed towns such as Granville; the (then) mayor, Frank P. Zeidler, complained about the socially destructive "Iron Ring" of new municipalities incorporated in the post–World War II decade. Analogously, semi-rural communities, such as Oak Creek, South Milwaukee, and Franklin, formally incorporated as discrete entities to escape urban annexation. Wisconsin state law had allowed Milwaukee's annexation of such rural and suburban regions that did not qualify for discrete incorporation per the legal incorporation standards.
Desegregation of schools
In some areas, the post–World War II racial desegregation of the public schools catalyzed white flight. In 1954, the US Supreme Court case Brown v. Board of Education (1954) ordered the de jure termination of the "separate, but equal" legal racism established with the Plessy v. Ferguson (1896) case in the 19th century. It declared that segregation of public schools was unconstitutional. Many southern jurisdictions mounted massive resistance to the policy. In some cases, white parents withdrew their children from public schools and established private religious schools instead. These schools, termed segregation academies, sprung up in the American South between the late 1950s and mid-1970s and allowed parents to prevent their children from being enrolled in racially mixed schools.
Upon desegregation in 1957 in Baltimore, Maryland, the Clifton Park Junior High School had 2,023 white students and 34 black students; ten years later, it had twelve white students and 2,037 black students. In northwest Baltimore, Garrison Junior High School's student body declined from 2,504 whites and twelve blacks to 297 whites and 1,263 blacks in that period. At the same time, the city's working class population declined because of the loss of industrial jobs as heavy industry restructured.
In Swann v. Charlotte-Mecklenburg Board of Education (1971), the Supreme Court ordered the desegregation busing of poor black students to suburban white schools, and suburban white students to the city to try to integrate student populations. In Milliken v. Bradley (1974), the dissenting Justice William Douglas observed, "The inner core of Detroit is now rather solidly black; and the blacks, we know, in many instances are likely to be poorer." Likewise, in 1977, the Federal decision in Penick v. The Columbus Board of Education (1977) accelerated white flight from Columbus, Ohio. Although the racial desegregation of schools affected only public school districts, the most vehement opponents of racial desegregation have sometimes been whites whose children attended private schools.
A secondary, non-geographic consequence of school desegregation and busing was "cultural" white flight: withdrawing white children from the mixed-race public school system and sending them to private schools unaffected by US federal integration laws. In 1970, when the United States District Court for the Central District of California ordered the Pasadena Unified School District desegregated, the proportion of white students (54%) reflected the school district's proportion of whites (53%). Once the federally ordered school desegregation began, whites who could afford private schools withdrew their children from the racially diverse Pasadena public school system. By 2004, Pasadena had 63 private schools educating some 33% of schoolchildren, while white students made up only 16% of the public school populace. The Pasadena Unified School District superintendent characterized public schools as "like the bogey-man" to whites. He implemented policies to attract white parents to the racially diverse Pasadena public school district.
Checkerboard and tipping models
In studies in the 1980s and 1990s, blacks said they were willing to live in neighborhoods with 50/50 ethnic composition. Whites were also willing to live in integrated neighborhoods, but preferred proportions of more whites. Despite this willingness to live in integrated neighborhoods, the majority still live in largely segregated neighborhoods, which have continued to form.
In 1969, Nobel Prize-winning economist Thomas Schelling published "Models of Segregation", a paper in which he demonstrated through a "checkerboard model" and mathematical analysis, that even when every agent prefers to live in a mixed-race neighborhood, almost complete segregation of neighborhoods emerges as individual decisions accumulate. In his "tipping model", he showed that members of an ethnic group do not move out of a neighborhood as long as the proportion of other ethnic groups is relatively low, but if a critical level of other ethnicities is exceeded, the original residents may make rapid decisions and take action to leave. This tipping point is viewed as simply the end-result of domino effect originating when the threshold of the majority ethnicity members with the highest sensitivity to sameness is exceeded. If these people leave and are either not replaced or replaced by other ethnicities, then this in turn raises the level of mixing of neighbors, exceeding the departure threshold for additional people.