The population of migrants in Beijing was 416,000 less in 2012 than in 2011, a result mainly of the city's high cost of living, Beijing News reported Wednesday.

The city had 8.25 million migrants in 2011, and the figure was 7.84 million in 2012.

"Policy regulation, rising living costs and environmental pollution mainly contributed to the decrease," said Lu Jiehua, professor of sociology at Peking University.

The migrant population is spreading outward to new districts such as southern Daxing district, southeastern Tongzhou district and northern Changping district, Lu said.

The population of Beijing totaled 20.7 million in 2012, about 5.3 million more than in 2005, and nearly half of the newcomers live in the new districts, the paper said.