THE worsening male and female imbalance in the Chinese population may pose serious social problems, experts have warned.Latest official demographic figures show men outnumber women by 18.1 percent in rural areas and 12.8 percent in urban areas.In most other countries, the male-female ratio average was 105:100, said Guo Zhigang, a Beijing-based expert in demographics. But he did not elaborate on the impact.The imbalance must cause a lot of problems to society, said Prof. Guo Cangping of the Renmin University of China. But the exact impacts were difficult to estimate, she said.Illegal abortions based on sex choice have been blamed for the imbalance. New regulations set to come into effect next month will outlaw sex tests during pregnancy.In many areas, especially in the countryside, people still prefer male babies because only men are regarded as able to carry on the ancestral line and because of the needs of labor for farm work.(SD News)