The percentage of men who have never been married by age 50 topped 20 percent for the first time on record in 2010, coinciding with another societal trend that finds more males are living on reduced incomes, according to a government survey.

The finding was revealed in a population census report by the National Institute of Population and Social Security Research in late March.

It will be included in the white paper on children and child-rearing to be compiled by the Cabinet Office in June.

Many office workers lost their jobs and university students failed to find work with high-paying large corporations after the economic bubble burst in the early 1990s, and as a result of subsequent recessions.

In the meantime, more people have found themselves underemployed, often working as temporary ranks, who in many cases are sent by subcontractors to work at the large firms as an expendable workforce when profits head south.

Thus many people have remained effectively poor in the world’s third-largest economy, where major companies prefer to hire new graduates, and used to promise employment through to retirement. While this so-called lifetime employment has been in decline, it still exists to a greater extent than is seen, for example, in the United States and European countries.

“It’s all economic reasons. Men with low income are not picked” by women for partners, said Masahiro Yamada, a professor of family sociology at Chuo University. “Most married men have full-time jobs.” Marriage is unlikely if a man doesn’t earn at least ¥3 million a year, he added.

Company workers earned on average ¥4.12 million in 2010, with male workers earning ¥5.07 million and females ¥2.69 million, according to the National Tax Bureau.

Yamada rejects the theory that men of medium to high income increasingly opt to stay single because they do not see the advantage of marriage. “Such men have always existed and their numbers aren’t high enough to influence statistics,” he said.

Though there are no exact corresponding statistics, it’s clear the percentage of men who have never married by age 50 is higher in Japan than in other developed countries, according to the population institute.

The institute gathered the roughly corresponding data from the Netherlands, U.S., Britain, Canada, France, Norway, Sweden and South Korea in the same report. Between 1999 to 2003 the rates were lower in every country except Sweden. South Korea had the lowest figure, with 2 percent in 2000, followed by the U.S. with 9.7 percent in 2000. The figure in Sweden was about 27 percent in 2003.

Japan’s percentage, compiled every five years, has risen since 1955, when it was just 1.18 percent. In 1990 it was 5.57 percent, and after the burst of the economic bubble, it soared rapidly to 8.99 percent in 1995, 12.57 percent in 2000, 15.96 percent in 2005 and 20.14 percent in 2010.

While not every man’s income has fallen, the distance between poor and wealthy middle-aged men has widened. Poor men tend to stay poor their entire lives and, in a country where women generally earn far less than men, they presumably are less-attractive marriage candidates.

The percentage of middle-aged men and women who have never been married is expected to grow because more and more younger members of society will be less likely to secure steady, full-time employment to carry them to age 50, Yamada said. The percentage of men will probably go up to and hover around 30 percent, while the figure for women will be more than 20 percent, he added.

To tackle the problem, society must make it easier for married women to work and make a decent amount of money, and ensure better terms of employment for young people, Yamada said.

In 2010, 10.61 percent of women were unmarried at age 50, up from 5.82 in 2000 and 7.25 percent in 2005.

Statistics in the report also show people are getting married later. Almost 72 percent of males and 60.3 percent of females aged 25 to 29 in 2010 had never married. Among those 30 to 34, 47.3 percent of men and 34.5 percent of women also had never wed.

Over 35 percent of men and 23.1 percent of women were still single between the ages of 35 and 39.

While more are staying single, it doesn’t mean they don’t want to marry.

In a separate survey released by the institute last November, 86.3 percent of men and 89.4 percent of women aged 18 to 34 said they “will be married in the future.”

The reason most commonly cited for staying single — 46.2 percent of men and 51.3 percent of women — is that they had not met a suitable partner. The “lack of money for marriage” was the No. 3 reason for men, cited by 30.3 percent.

Statistics from last October also showed the number of middle-aged unmarrieds living with their parents for financial help, so-called parasite singles, is on the rise, an indication of the persistence of underemployment.

In 2010, 2.95 million people aged 35 to 44 were living with their parents, or 16.1 percent of the age group, according to the Internal Affairs and Communications Ministry. The percentage was 10 percent, with 1.59 million people, in 2000 and 5.7 percent, with 1.12 million people, in 1990.

Among them, the unemployment rate was 11.5 percent in 2010, compared with 4.8 percent for the age group as a whole.

Parasite singles in their 20s and 30s emerged as a big social issue in the 1990s, though back then they were thought to be preferring an easy life that allowed them to spend most of their disposable income on leisure activities instead of rent and utility bills.