During the 20th century, especially after the middle, the city is going through a large increase in population and is consolidating as regional hub for trade and services, becoming one of the richest cities in Brazil and pioneer in urban solutions. In the 1940s and 1950s, Alfred Agache, co-founder of the French Society for Urban Studies, was hired to produce the first city plan. It emphasised a "star" of boulevards, with public amenities downtown, an industrial district and sanitation. It was followed when possible, but was too expensive to complete.