Golden brand

Chen Ci, Party chief of Haikou, said good air quality is a "golden brand" and that any measures, including traffic control and clean energy, should be considered to maintain the brand.

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Property investment in Hainan has been boosted by worsening air quality elsewhere in China, according to a report from the Hainan provincial housing and urban-rural development bureau.

The total investment in real estate development on the island province surged to nearly 120 billion yuan ($19.5 billion) in 2013, a 35 percent year-on-year increase, about 21 times the figure for 2004, according to the bureau.

Yunnan also wants to keep its claim on the golden brand of clean air and low pollution.

Ren Jianzheng, president of Northstar Group in Yunnan, who serves as an NPC deputy, said Yunnan has consistently implemented policies on the tourism industry to reduce environmental contamination.

"Yunnan never had smog and is among the few provinces with no food safety violations. You won't find better water, food and air," he said.

Chen Xiaofeng, a real estate agent in Kunming, capital of Yunnan, said China's middle and upper classes often pay millions of yuan for a house in the province.

In the Dali Bai autonomous prefecture, a famous travel destination in northwest Yunnan, a one-courtyard house near the Erhai Lake can sell for around 9 million yuan ($1.5 million), Chen said.

"When they have spare time, they can go to Yunnan and take a break from the fast pace of work or travel around for several days. That's more enjoyable than being in Beijing or Shanghai," he said.

Zheng Xin and Hu Yongqi contribute to the story.

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