A city with features of a post-industrial civilization. Service industries predominate, with a significant quaternary sector, and footloose enterprises exist, generally on lovely open area on the outskirts of town. Additionally, see "entrepreneur" and "information city." Post-industrial cities emerged after World War II as industrial centers lost their competitive advantage and were forced to adapt to new markets or go out of business. The decline of industry has created a need for alternative sources of income to support those left without jobs in the traditional sense. Cities that successfully transform themselves into service centers are likely to remain economically viable in the long run. Some factors common to all post-industrial cities are: a population that is increasingly made up of marginal workers; high rates of unemployment, especially among young people; reduced funding for local government; and increased segregation by class, race, and religion. These problems are exacerbated by poor planning decisions made by central government agencies at a national level. Cities across the United States have been experiencing dramatic changes since the 1970s, when deindustrialization began to take place. This phenomenon can be attributed to many factors, but most economists agree that trade agreements and deregulation are the main causes. As factories closed down or moved overseas, thousands of people were left with no choice but to look for work elsewhere.