Instead, as a result of high-tech industry and services, the area grew largely without overall planning to become perhaps the most densely populated region of the UK. In the late 20th century mass manufacturing of ordinary commodities declined leaving several town and city neighbourhoods impoverished and suffering unemployment, however by the early 21st century high income and retirement properties came to dominate some neighbourhoods, particularly close to universities, and many suburbs and exurbs. Centrally planned building programmes included large estates, carefully connected by new road networks, of commercial and residential use by Hampshire County Council's architects, led by Colin Stansfield Smith. Otherwise development has tended to be a case-by-case basis for retail parks, business parks and housing.