NEW YORK • Last week, Sonia Rykiel, the French house owned by First Heritage Brands that has been undergoing something of a buzz renaissance under designer Julie de Libran, announced it was incorporating its more affordable Sonia by Sonia Rykiel line into its main one, the better to rationalise the brand image and message to customers.

Or, as Mr Jean-Marc Loubier, chief executive of First Heritage, said, to "refocus on one clear offering". There has been a lot of hoo-ha since the announcement, which also revealed that a significant portion of the company's employees were being laid off - 79 of 330 - and that some stores would close, as well as over what that might mean about the admittedly challenged state of the business.

But the decision to absorb the little sister collection into the core line may be even more meaningful as a reflection of a broader trend in fashion. After all, the Rykiel consolidation echoes that of Burberry, which announced last year that it was combining Burberry Prorsum, Burberry London and Burberry Brit into a single collection.

And that, in turn, echoed Marc Jacobs, which decided last year to stop creating and showing Marc by Marc Jacobs and instead make it all Marc Jacobs - not to mention the decision by LVMH Moet Hennessy Louis Vuitton to suspend the Donna Karan main line and focus on DKNY, its contemporary sibling. All of them following the decision by Dolce & Gabbana in 2011 to stop producing a stand-alone D&G collection.

And it comes in the wake of an announcement this summer that Ralph Lauren would streamline its business to concentrate on three brands, as opposed to more than twice that number, as well as before the imminent debut collection of Raf Simons as chief creative officer at Calvin Klein, charged with uniting that brand's myriad lines under a single vision.

Vivienne Westwood and Paul Smith have also reduced their collection counts, the first folding her Red Label into the main line (Andreas Kronthaler for Vivienne Westwood) and the second combining smaller labels such as Paul Smith Men's, Paul Smith London, PS by Paul Smith and Paul Smith Jeans into two: Paul Smith and PS by Paul Smith.

The changes all add up to a major shift in how fashion is thinking about what consumers want and need. Instead of a lot of style stratification by price, now, it is all about one unified style point of view.

It is an acknowledgment that what makes one desire a piece of clothing, a bag or a pair of shoes - what we are looking for when one goes into a store or to a website - is less dictated by numbers than a clear identity in which one sees oneself. Only after that exists do the figures come into play.

But such consolidation is not cheap for the brands because of the restructuring involved. As Mr Luca Solca, head of luxury goods at Exane BNP Paribas, points out: "It is a good idea if you need to shore up exclusivity perception and reinforce brand desirability over the long term. But it often requires a major financial sacrifice." Which suggests that the brands themselves believe they are responding to a permanent shift in buying habits. Otherwise, the change would not be worth the effort.

So, while the moves towards fewer labels may partly have to do with long-term cost-cutting, they probably also have to do with a bet on even longer-term sales growth. In other words, this is not a fad.

There is still a smattering of names that believe in the older system of segregation.

Armani recently opened a major Emporio Armani store in Paris, reaffirming its commitment to that line. Max Mara still shows Sport Max on the Milan ready-to-wear schedule. But they are exceptions rather than the rule.

NYTIMES