BEIJING By Chinese standards, Chu Yang and Geng Chen should have had a child years ago. The married couple in their early 30s are always reminded of that by family when they return home for the spring festival holidays.

"They say we're too different and that we're weird and pathetic," said Chu, who runs a trendy boutique with his wife in an aging section of Beijing.

But Yang and Chen have their reasons. They point to uncertainties that have accompanied China's breakneck development, including a string of food safety scandals and a deadly crash on one of the nation's showcase high-speed rail lines. Then there's the soaring cost of living, underscored by the worst inflation in three years and a property bubble that refuses to deflate.

Experts have long cited three decades of strict population control for China's looming demographic time bomb. Declining birthrates and a rapidly aging society threaten to sap the country of its greatest economic asset: human labor. Some are calling for the nation's one-child policy to be relaxed.

But Chu and Geng show why it may not matter. Economic and social pressures are loosening the filial obligations that have long bound Chinese society. The younger generation longs for more personal comfort. Many Chinese wouldn't have larger families even if they were free to do so. Some want no children at all.

Gender imbalance

Other social changes are also depressing the country's birthrate. Some women are choosing to marry later if at all. And the cultural preference for boys - aided by sex-selection technology - has created an alarming gender imbalance in a nation with 1.3 billion people. There are now 118 males for every 100 females in China.

Tens of millions of men could be left without marriage partners, a major threat to social stability.

It all spells trouble for the world's most populous country. China's economic miracle was built on the backs of its working-age adults, who will soon retire and find fewer children to pay for their care.

The number of Chinese under 14 has declined 6.3 percent in the last decade and now accounts for just 16.6 percent of the population.

Meanwhile, the share of Chinese age 60 and older is expected to more than double to 30 percent of the population by 2050.

Southern Guangdong province asked the central government in July for permission to pilot a program that would allow couples to have two children if one spouse is an only child.

At least five other provinces have reportedly considered a similar program. Many cities allow couples leeway if both spouses have no siblings.

Exceptions already exist for some rural couples and ethnic minorities, among others.

But it may not do much good. Dogs are the new bundles of joy for some childless families, giving rise to a phenomenon known as ding chong, or "double income with pet."

And more Chinese women, particularly those with college degrees and white-collar jobs, are delaying marriage and childbearing - or avoiding them altogether. The divorce rate climbed to 8.5 percent last year, the fifth year in a row it has risen.

Unmarried women

Chinese have dubbed these unmarried females sheng nu, or "leftover women." They're often pitied on TV game shows and reality programs with titles such as "Let's Date" and "If You Are the One."

Many single women bristle at the stereotypes. The problem, some say, is a dearth of worthy bachelors.

"There's a lot of excellent women who are still single who own a car, own an apartment and have a career, but can't find the right other half," said a 28-year-old Beijinger who would give only her last name, Zhang. "We don't want to compromise. We have high expectations."

The rising cost of living has also discouraged couples from starting families. Of 2,000 couples surveyed by the Shanghai Academy of Social Sciences, 45 percent didn't want a second child, mainly because of costs for education, nannies, infant formula and the like.

A typical 1,000-square-foot apartment in Beijing now costs about $311,000, or 40 times the annual salary of the average resident.

Still, home ownership is almost a prerequisite in China for raising a family. Men who don't own real estate are at a serious disadvantage when wooing a mate.