<P> 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 . </P> <P> 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 . </P> <P> 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 . </P> <P> About 800,000 out of an earlier total population of 5.2 million whites have left South Africa since 1995, according to a report from 2009 . (Apartheid, a system of segregation of whites, blacks, and people of other races, had ended in 1994 .) The country has suffered a high rate of violent crime, a primary stated reason for emigration . Other causes include attacks against white farmers, concern about being excluded by affirmative action programs, rolling blackouts in electrical supplies, and worries about corruption and autocratic political tendencies among new leaders . Since many of those who leave are highly educated, there are shortages of skilled personnel in the government, teaching, and other professional areas . Some observers fear the long - term consequences, as South Africa's labor policies make it difficult to attract skilled immigrants . The migration of whites in South Africa was facilitated by the creation of immigration routes into European countries for people with European ancestry . For instance, the British government introduced the notion of patriality to ensure white people of British ancestry from Africa could settle in the UK . In the global economy, some professionals and skilled people have been attracted to work in the US and European nations . </P>

How were the suburbs of the 1950s different from the earlier suburbs of the 1920s