The third theoretical explanation of gentrification is political-economic and is divided into two approaches: traditional and Marxist. The traditional approach argues that economic and political factors have led to the invasion of the inner-city, hence the name political-economic. The changing political and legal climate of the 1950s and 1960s (new civil rights legislation, anti-discrimination laws in housing and employment, and desegregation) had an "unanticipated" role in the gentrification of neighborhoods. A societal decrease in acceptance of prejudice led to more blacks moving to the suburbs and whites no longer rejected the idea of moving to the city. The decreasing availability of suburban land and inflation in suburban housing costs also inspired the invasion of the cities. The Marxist approach denies the notion that the political and economic influences on gentrification are invisible, but are intentional. This theory claims that "powerful interest groups follow a policy of neglect of the inner city until such time as they become aware that policy changes could yield tremendous profits". Once the inner city becomes a source of revenue, the powerless residents are displaced with little or no regard from the powerful.