The informal economy has had a significant presence in the housing sector. The informal sector has been the base of urban development in Peru. The majority of Lima has been developed completely outside the law. Lima is a city of 8 million people. During the last 40 years, migrants from the countryside have invaded the public and private lots creating marginal urban neighborhoods, or slums. In the case of Peru, there is great economic, social, and political importance to the development of the informal housing sector. It is economically significant because people have made investments in their own informally built homes amounting to $8 or $8.5 billion. This investment has been made with no government aid. It is socially significant because traditionally in Peru, the lower classes had not been property owners. Now there is an emergence of a new proprietary class. It is politically significant because only the property owners can fight for their rights and now these people own property.