Urbanization has hurt the poor in Sài Gòn, the first-ever survey on incomes has found, while workers’ minimum and maximum wages differ by a factor of almost seven.

Nguyễn Quang Vĩnh, a senior researcher at the Sài Gòn Institute for Development Studies, said the creep of urbanization has forced the poor to the outskirts and less developed areas.

''Many poor have become migrants in their own city,'' he told a conference that was held last week to announce the start of another research project, this one on the urban poor, by the institute, the city’s Statistics Agency, and the United Nations Development Program.

According to government statistics, around 80,000 people in Sài Gòn live under the poverty line, which is set at $650.

The survey, done by researcher Lê Văn Thành of 720 workers in 12 districts, found the city’s average per capita income has risen to $2,500.

Nearly 48 percent of its residents have stable jobs and 4.5 percent were unemployed.

Around 24 percent of the respondents were satisfied with their earnings; their families spend more than half of their income on food and a fifth on education.

Families have an average of 4.6 members while the proportion of the population that is of working age at 69.7 percent.

Sài Gòn’s population is growing older, the report concluded.

Nearly half of the city’s residents have lived there for more than 25 years while the rate of migration to the city is constantly rising.