Zheng Bingwen, head of the Global Pension Fund Research Center at the Chinese Academy of Social Sciences, said insufficient facilities in some remote areas also delay transfers.

The circular stipulates that pension account transfers and continuation should be completed within 30 days.

The number of migrant works who participated in basic endowment insurance declined by 760,000 from the end of 2011 to the end of March this year, according to the Ministry of Human Resources and Social Security.

Yin Chengji, a spokesman for the ministry, said labor flow has led to a smaller number of endowment insurance participants.

Lu partly attributed it to the inefficiency of the pension accounts transfer.

"Complicated procedures and inefficient operation make many migrant workers shy away from the pension system," she said.

Chinese law stipulates that workers can collect pensions after they pay into endowment insurance for 15 years.

To make the project more efficient, Lu suggests that a unified information platform be set up, the same software used across the country and more skilled personnel trained.

Regarding the other four social insurance programs, Zheng said the benefits of basic medical, unemployment, work injury and maternity insurances can be used immediately, so it's unnecessary to consider their transfer and continuation.