Officially, sales in Shanghai, Nanjing and Hangzhou in the first half of the year were down 50%.

FORBES: Reality Check For China's Real Estate

Property transactions by floor space in some major cities, such as Beijing, Shenzhen, Hangzhou, Nanjing and Chongqing rose in May from a year earlier, according to statistics from data provider China Real Estate Information Corp.

WSJ: China Steps Up Support for Parts of Housing Market

But after just two nights, the government says the PM 2.5 air pollutant index has soared in Beijing, Shanghai, Nanjing, Hangzhou, Xian and other major cities, Southern Metropolis Daily reports.

BBC: China media: New Year haze

The report found that one-third of luxury consumption in China today came from just nine markets: Chongqing, Dongguan, Foshan, Guangzhou, Hangzhou, Nanjing, Shenzhen, Tianjin and Wenzhou.

FORBES: Long-Term Consumer Outlook For China Luxury