Legal prohibition of some types of discriminatory conduct may be morally acceptable even though the conduct being prohibited would not be immoral in the absence of legal prohibition. Consider Thomas Schelling's analysis of patterns of racial segregation in residential housing. If one sees a sharply segregated housing segregation pattern (for example, African-Americans living next to African-Americans, whites living next to whites, and African-Americans living next to whites only at the neighborhoods - edges) even though there is no legal requirement that forces this result, one might suppose that what explains the segregation is a strong desire of almost all members of one or both groups not to live in proximity to any members of the other group. Schelling presented a simple model of the dynamics of residential housing choice that showed that mild racial preferences could lead to strongly segregated outcomes. For example, if nobody wants to live in a neighborhood in which members of his racial group are a minority, and individuals occasionally move in and out of neighborhoods, eventually a strongly segregated pattern emerges. In other words, segregation can emerge even if no one is averse to living in proximity to members of another race.
Richard J. Arneson,
What Is Wrongful Discrimination?,
San Diego L. Rev.
Available at: https://digital.sandiego.edu/sdlr/vol43/iss4/4