The increase of population brought with it the increase in the size of what is now called Greater Guadalajara, rather than an increase in the population density of the city. Migrants coming into Guadalajara from the 1940s to the 1980s were mostly from rural areas, who lived in the city center until they had enough money to buy property. This property was generally bought in the edges of the city, which were urbanizing into "fraccionamientos", or subdivisions. In the 1980s, the city was described as a "divided city" east to west based on socioeconomic class. Since then, the city has evolved into four sectors, which are still more-or-less class centered. The upper classes tend to live in Hidalgo and Juárez in the northwest and southwest, while lower classes tend to live in the city center, Libertad in the north east and southeast in Reforma. However, lower class development has developed on the city's periphery and upper and middle classes are migrating toward Zapopan, making the situation less neatly divided.(napolitano21-22).
Since 1996, activity by multinational corporations has had a significant effect on the economic and social development of the city. The presence of companies such as Kodak, Hewlett-Packard, Motorola and IBM has been based on production facilities built just outside the city proper, bringing in foreign labor and capital. This was made possible in the 1980s by surplus labor, infrastructure improvements and government incentives. These companies focus on electrical and electronic items, which is now one of Guadalajara's two main products (the other being beer). This has internationalized the economy, steering it away from manufacturing and toward services, dependent on technology and foreign investment. This has not been favorable for the unskilled working class and traditional labor sectors.
On April 22, 1992, numerous gasoline explosions in the sewer system over four hours
