David Shaw wears long pants to protect his shins when he's skateboarding, or if it's rainy or very cold. Or for a special event, such as his eighth-grade graduation.
Otherwise, forget it.
"The only other time I wear pants is if all my shorts are dirty,'" said the 14-year-old from Newport Beach, Calif., shopping with his mom and little brother at the Metro Point shopping center in Costa Mesa, Calif., recently.
Teenage boys are spending less these days on long pants, content instead to buy shorts or simply keep wearing -- and re-wearing -- the same old jeans and cargo pants.
Sales of pants for teenage boys fell more than 10 percent and jeans sales dropped almost 15 percent in the 12 months ended April 30, according to market research firm NPD Group.
By comparison, men's apparel sales rose about 4 percent to nearly $52 billion in the same period.
Pants sales are more important than shorts sales for retailers because they typically cost more and have a higher profit margin. Moreover, pants are sold year-round and are considered a more stable part of a retailer's business.
At the root of the problem is a shortage of tempting trends, apparel experts say.
"The malaise is really industrywide," said Elizabeth Pierce, an analyst with Sanders Morris Harris.
"Most companies will tell you they don't see any light at the end of the tunnel, because there's been nothing new in men's bottoms for a couple of years."
Teen pants sales will become increasingly important for retailers in the coming months, as they begin stocking stores with back-to-school merchandise.
Yet young males' ho-hum attitude about buying pants probably is exacerbating retailers' problems.
"A guy can wear the same pair of pants five days in a row," said Marshal Cohen, senior retail analyst at NPD Group. "He couldn't care less."
And without a "must-have" trouser style to refresh their wardrobes, young men won't be compelled to shop.
"We've been cargo-panted to death," said David Wolfe, menswear expert and creative director of Doneger Group, a New York fashion-trends consulting firm.
Although females tend to gravitate to clothes, males often direct their attention -- and dollars -- to electronic gadgets, Pierce said. So if there are no new styles to lure him, his old pants aren't worn to the point of indecency or "his significant other doesn't tell him he looks likes an idiot," a guy generally won't go shopping for clothes, she said.
In Southern California, where the weather is rarely gloomy and never frigid, many teens just don't see the point of wearing long pants when they can wear droopy shorts, which hang below the knee.
The sale of shorts to teen-age boys jumped 19 percent in the year ended April 30.
The sale of guys' swimwear, which increasingly is worn on the street, surged 23 percent, a trend that benefits California-based youth apparel companies such as Pacific Sunwear and Huntington Beach, Calif.-based surf-wear maker Quiksilver Inc.
Fatma Sahin, 40, has been fighting a losing battle trying to get her 12- and 13-year-old sons to wear long pants since moving to Westminster, Calif., from Turkey 3 1/2 years ago.
"I still try," Sahin said during a recent outing to the Westminster Mall with son Arda and husband Arslan.
"She tells us to stop wearing shorts, it's too cold outside," said Arda, 12. His response: "Who cares?"
"It doesn't make me feel comfortable" to wear long pants, he said. "And when you do sports, it makes you slower and stuff."
A love of shorts may be an inherited trait. Arslan Sahin, a 42-year-old truck driver, admits that even he recently went nine months without slipping into a pair of trousers, donning shorts instead.
Certainly teen-age boys haven't sworn off long pants altogether; in many parts of the United States, wearing shorts year-round isn't an option. Some young shoppers even say they like current pants styles, including hip-hop-inspired garb such as baggy jeans and warm-up suits, a la rapper Eminem.
But many guys won't even try on trousers, a problem San Francisco-based Gap Inc. tackled recently with its "Try On Our Pants" promotion, which whacked 20 percent off any purchase of $50 or more for customers who were willing to at least slip into a pair of khakis. Women were allowed to participate, but the "khaki relaunch" promotion was designed to lure men into the dressing rooms at Gap's 1,300 U.S. stores, spokeswoman Jordan Benjamin said.
"We rewarded them simply for trying them on," she said. "We were confident that if they would try them on it would result in incremental sales for us."
The effort pushed sales "above expectations" for March, Benjamin said, declining to give specifics.
Meanwhile, manufacturers and retailers have been seeking solutions. Tarrant Apparel Group, for example, hired designer Arnold Zimbert to create casual pants that it hopes will be "as revolutionary as the chino," said Gerard Guez, the Los Angeles company's chief executive.
"It's washed and it's wrinkled," he said. "We beat up the clothes and give them an almost vintage-y look."
Early response from retailers has been "extremely encouraging," he said.
Other companies, including Gap and Levi Strauss & Co., have begun trying to tempt males with stain-resistant pants. But some apparel experts question the wisdom of this approach, because many guys won't buy new pants until their old ones are thrashed.
"Now they're making khakis you never have to replace," said Wolfe, the fashion consultant. "They're stain resistant, wrinkle resistant and bulletproof."
Besides, teen-age boys aren't exactly consumed with worry about whether they might get a spot on their trousers.
"It amazes me," Wolfe said, "that so many are pinning their hopes on stain-resistant khakis."
Levi spokeswoman Linda Butler said the San Francisco-based manufacturer's anti-stain khakis were well received by men when they were introduced last fall. This year, the "stain defender technology" is being added to more men's styles, boys' khakis and even some women's clothes, she said. She declined to comment on pants sales.
Retailers are keeping their eyes peeled for the next big trend.
"As soon as someone figures it out, they'll fill their stores with it," said Pacific Sunwear President Tim Harmon, a retail-industry veteran. "And the rest of us will be chasing."