A survey released on Wednesday reveals that the wealth gap in China is still severe although a key measure of income disparity of 2012 fell slightly compared to that of 2010.

The survey, which was conducted by the Institute of Social Science Survey affiliated with Peking University, showed that the Gini coefficient, which is a key measure of income and wealth distribution, fell to 0.49 from 0.51 in 2010. But the figure is still higher than the world average of 0.44.

The researchers of the institute made their conclusion based on a sample survey of 15,000 households from 25 provinces and municipalities across China.

Gini readings above 0.4 are often seen as indicative of a level of inequality that could make social unrest more likely.

Xie Yu, an author of the survey report, told the Global Times that the decrease of the Gini reading is due to the narrowing income gap between rural areas and urban areas, as well as that between middle and high-income groups.

In January 2013, the National Bureau of Statistics published Gini coefficient data for 2012 and the decade prior. The reading fell to 0.474 in 2012 from a peak of 0.491 in 2008. 

However, the public have raised questions about the accuracy of the reading, saying it is too low and does not reflect reality.

The government figure is much lower than the one from a survey published in late 2012 by researchers from the Sichuan-based Southwestern University of Finance and Economics.

Their research found that the Gini coefficient is as high as 0.61 in 2010, about 50 percent above the "risk level" for social unrest, making China one of the world's most unequal countries. 

The income of the poorest family groups in the survey only accounts for some 0.1 percent of the total income, while the richest groups have 23.4 percent of the total income, the research found. 

Xie also noted that the low-income group, especially in cities and townships, has a lower rate of increase in their income compared to the middle-income and high-income groups. 

"The fact of the significant gap between the richest group and the poorest group shows that the wealth gap is widening and severe, which might stir some instability in society," Xie said.

Du Xiaoshan, a researcher at the Rural Development Institute of the Chinese Academy of Social Sciences, told the Global Times Thursday that the government should help to speed up the income increase of the middle-income group and provide more employment opportunities to low-income groups.

"This is the key to narrowing the wealth gap. Meanwhile, a more sophisticated social welfare system is also crucial to solve the problem," Du noted. 

He added that the rich should be encouraged to get involved in charity and the tax policy can also be used to narrow the gap.