Are America's biggest retailers having a wardrobe malfunction? Former clothing powerhouses like Gap, J.Crew, and Abercrombie—once juggernauts in the industry—are facing flagging styles. In the past year, Gap and J.Crew sales have both  declined by 10%; Abercrombie's by 14%.

Why? "Both got caught in several currents, several strong wind currents," says historian Nancy Koehn.

The first is the rise of "fast fashion," where retailers take styles off the runway and bring them to market extremely quickly, sometimes within days. Competition from overseas retailers like H&M, Zara, and Uniqlo—who offer such styles at rock-bottom prices—has drawn American consumers away from places like Gap and J.Crew.

The other current has to do with what Koehn calls "bricks and clicks"—that is, the rise of online storefronts as being just as lucrative as their brick-and-mortar counterparts.

"They've lost their mojo," Koehn said. "You've got to bring people into stores, you've got to get them online."

So is the solution that old adage: 'if you can't beat 'em, join 'em?' Not necessarily, Koehn says. In the rush to emulate fast fashion and the consumer's endless desire for the newest trends and styles, companies like Gap, J.Crew. and Abercrombie have slowly lost what it was that made them unique in the first place, abandoning staples and classics for "fast fashion" pieces.

"It's very seductive, and it makes some real sense to take your classics and take them to the edgy side of the spectrum a little bit," Koehn said.

"But if you start doing that year after year, season after season...suddenly you've lost some of your core customers, and the sense of: 'Oh, I can go get my very flattering Spandex and cotton khakis that look great on me, because they're not there." 

To hear more from Nancy Koehn, tune in to Boston Public Radio above.