The government helped more than 3.7 million migrant workers get their unpaid wages totaling more than 35 billion yuan ($5.1 billion) last year.

However, the long-standing problem of migrant workers failing to get paid remains a difficult issue due to the chaotic construction market and low penalties for breaking the law, officials said.

The total of unpaid wages decreased by 16.7 percent compared with 2015, said Wang Cheng, head of labor security supervision at the Ministry of Human Resources and Social Security.

Wage defaults have been a problem in China, especially before Spring Festival, which falls on Jan 28 this year. Migrant workers who fail to get their wages and can’t get back home for the most important festival in China often win widespread sympathy.

Lu Aihong, another official with the ministry, told a news conference on Jan 23 that during a campaign from Nov 15 to Jan 15, the government helped more than 766,500 migrant workers get unpaid wages totaling 9.2 billion yuan.

Also on Jan 23, Qiu Xiaoping, vice-minister of human resources and social security, told people.com.cn in a video interview that inspections have been made in labor-intensive industries during a nationwide campaign, and local governments have been asked to dispatch officials to conduct reports about wage defaults.

However, Wang said that wage defaults remain a problem, and most of the cases involve construction workers.

It’s a common practice that many migrant workers are only paid a small amount of their monthly wage to cover living expenses and get the remaining money when a project is complete, or before Spring Festival.

Many construction projects are subcontracted multiple times, leaving some subcontractors almost no profit margin, which leads to wage defaults, he said.

Another reason for the long-standing problem is that the penalty for breaking the law is still low, Wang added.

An amendment to the Criminal Law in 2011 made defaulting on wages a crime and said an employer may be fined and sentenced to jail for up to three years if the amount of unpaid wages was “relatively large”, which the Supreme People’s Court defined as being between 5,000 yuan and 20,000 yuan over more than three months.

Wang said very few people have been sentenced to prison and some local courts will free the employers if they pay migrant workers after being sued. Meanwhile, employers will only be fined up to 20,000 yuan if they still refuse to pay workers’ their wages within a time limit set by law enforcement officers.