The resumes fluttering in the wind, hanging from clotheslines like so much drying laundry, relay the hard facts: age, height, education, property, salary. Welcome to the outdoor marriage market at Shanghai's People's Park, where parents arrive every weekend in search of a match for their unwed daughters.

Such marriage markets exist in many cities in China, and a closer look at the resumes reveals that many of the single ladies fall into similar categories: highly educated, career-driven, and not getting any younger.

In China, single women over 30, and even in their mid-to-late 20s, can find themselves branded as sheng nu, or "leftover women", and are often under intense pressure to get married.

In a different world, China's gender ratio might favor women; but because of strong social tradition, the opposite is true. It has long been believed here that women must marry up in terms of income, education and age. And as Chinese women climb the social ladder -- becoming more educated and earning higher salaries -- the pool of viable suitors is shrinking fast.

The most highly-educated women often end up without partners altogether, as more and more professionals say they just can't find men who make the grade.

What's more, marriage at a young age has long been the norm in China. In 1950, the average age for urban Chinese women to marry for the first time was just under 20. By the 1980s it was 25. Now it's about 27.

So it's hardly surprising that women face criticism for choosing to stay single, especially as the countryside fills up with men who can't get married because they outnumber marriage-age women.

It's not just moms and dads who want their grown daughters to find spouses, but also government agencies and academics, who see this massive group of unmarried women as a potential source of social instability.

Many women have been accused in the media of being overly focused on finding men with bigger houses and fancier cars, instead of more down-to-earth prospects, such as true love. The phenomenon has also fueled a wave of dating shows that glut Chinese television.

A dating gameshow called "Fei Cheng Wu Rao," or "If You Are the One," has become particularly popular. In each episode, 24 women sort through male contenders in search of the date-worthy, and material concerns often take precedence.

Serials like "The Price of Being a Sheng Nu," "Go, Go, Sheng Nu," and "Even Sheng Nu Get Crazy" cram TV schedules, and all of them have similar plotlines: smart, beautiful, successful women trying everything to get a man, according to a recent report in the Los Angeles Times.

"Sheng nu are being demonized," said Sandra Bao, who founded a social group called "Leftover Attitude" in Shanghai to support unmarried professional women. "Parents are pressuring us, the media label us, there's a whole industry of matchmakers and others out there telling us it's a problem to be single."

She noted that many modern, single women in China enjoy their independence and feel comfortable holding out for the right man, even as they grow older. "They don't want to make compromises because of age or social pressure," she said.

A 29-year-old marketing executive, who uses the English name Elissa, says being single at her age isn't totally bad. "Living alone, I can do whatever I like. I can hang out with my good friends whenever I like," she says, "and I can do a lot of stuff all by myself - like reading, like going to theaters."

Sure, she says, her parents would like her to find someone, and she has gone on a few blind dates, for their sake. But, she says, they've been a "disaster".

Elissa says she'd love to meet the right man, but it will happen when it happens. Meanwhile, life is good - and she has to get back to work.