China’s army of migrant workers, a source of cheap labour in the world’s second biggest economy, is greying and becoming less mobile, according to the latest annual survey conducted by the Chinese government. A report published by National Bureau of Statistics (NBS) on Monday showed that China had 288.36 million migrant workers at the end of 2018, a rise of 0.6 per cent from a year earlier. However, these migrant workers have become less willing to travel far from home to look for work, with many inland governments encouraging them to return home to start their own businesses. The National Development and Reform Commission, the country's top economic planner, issued a policy last year asking local authorities to offer grants to migrant workers returning home – but this is only part of the story. Government officials have said that China’s slowing economy, which has resulted in a spate of factory closures, may have accelerated the return home of migrant workers. The survey also found that China’s migrant workers are growing older . More than 22.4 per cent of migrant workers are now aged over 50, a rise of 1.1 percentage points from a year ago and 5.3 percentage points higher than five years earlier. As workers grew older, they tend to stay closer to home, the survey found. The average age for migrant workers taking local jobs was 44.9 years old, much older than the average age of 35.2 years for those working further from home. The proportion of migrant workers aged between 16 to 30, meanwhile, has fallen significantly for five consecutive years. Unlike their predecessors, the younger generation of workers tend to dislike traditional factory or construction site jobs. The survey showed that 115.7 million migrant workers took local non-farming jobs without actually leaving their hometown. By NBS’ classification, these workers still count as migrant. Meanwhile, 172.7 million left their homes to take jobs elsewhere. Among the 172.7 million who actually migrated, fewer are leaving their home provinces, with a 810,000 decline in the number of workers leaving their home province in 2018. The survey showed that an additional 1.62 million migrant workers took jobs within their home provinces. Zeng Yande, an official from the ministry of agriculture, said last November that around 7.4 million migrant workers returned to places near their hometowns, with some analysts suggesting that this could be due to factory closures in coastal areas, which forced migrant workers to return to their rural homes. Qiu Xiaopping, a deputy minister of human resources and social security, said in January that some Chinese migrant workers had lost their jobs due to China’s economic slowdown, another factor in their return home. As a result, the number of migrant workers in the Pearl River Delta, the manufacturing and export heartland in China’s south, fell by 1.86 million last year, to 45.36 million. The number of migrant workers in the Beijing-Tianjin-Hebei area, another industrial heartland, also dropped last year, by 270,000, the survey showed. While the survey does not provide any reason for the drop, Beijing’s less friendly policy towards migrant workers and Tianjin’s sluggish economy may have persuaded some migrant workers to leave. In 2018, the proportion of migrant workers engaged in the tertiary industry was 50.5 per cent, an increase of 2.5 percentage points over the previous year. The number of migrant workers in the manufacturing sector fell by 2 per cent, while those in construction dropped 0.3 per cent. The average salary for migrant workers was 3,721 yuan (US$553) last year, which was an increase of 6.8 per cent on 2017. However, there was a big disparity between the developed eastern region and the less developed northeastern provinces in terms of the rise in salary. In the prosperous east, the average migrant worker saw their salary rise by 7.6 per cent, compared to just 1.4 per cent in the northeast, considered to be China’s rust belt .