A labor ministry survey has found that people with irregular jobs now account for 40 percent of the nation's workforce. The continuing increase of such workers, who are typically paid less than full-time regular company employees and face unstable employment prospects, threatens to hamper sustainable growth of the nation's economy by undermining consumer demand. It could also result in a large percentage of the population lacking proper social security protection. The government and businesses must make serious efforts to improve the pay and other conditions of irregular workers.

One of the factors behind the increase in the number of irregular workers is the rise in part-time workers and elderly people on post-retirement re-employment contracts. According to the Health, Labor and Welfare Ministry's survey on diversification of employment forms, 19.62 million out of the nation's 52.4 million people on payroll as of October 2014 were irregular workers. Nearly 69 percent of them were part-time workers. While some 68 percent of regular full-time workers were males, about 64 percent of irregular workers were women. People 65 or older accounted for 11.9 percent of the irregular workers, up from 9.1 percent five years earlier.

The same survey also found that companies that reduced their full-time employees since 2011 — 27.2 percent of the total — outnumbered those that hired more regular workers since that year — 20.6 percent. This suggests that an increasing number of firms are replacing regular workers with irregular staff, including people on term contracts and temporary dispatch workers.