The phenomenon known as "vanity sizing" — the practice by clothing manufacturers of labeling garments with smaller size designations than their actual measurements correspond to, in order to flatter consumers and encourage purchases — had been documented and complained about for years. But a study published in 2012 that measured the actual waist dimensions of jeans labeled at specific sizes across multiple brands brought fresh attention to how extreme the distortion had become.

The findings were striking. Jeans labeled as 36-inch waist from certain brands measured at actual waistbands approaching 40 or even 41 inches. Armani was among the brands cited for particularly aggressive vanity sizing, with labeled 33-inch jeans measuring substantially larger in reality. H&M, at the other end, was noted for labeling garments closer to their actual measurements.

The practical effect of this is that a consumer buying across brands has no reliable way to know what size to buy without trying garments on or consulting specific brand measurement guides. The standard numerical size designation, which might logically suggest a standardized system, is in practice a marketing variable rather than a consistent physical measurement.

Fashion industry observers noted that vanity sizing had accelerated as average body measurements across Western populations increased — clothing companies found that customers were more likely to buy and less likely to return garments when the label displayed a smaller number than the garment's actual size. The flattery of the label translated, apparently, into purchase satisfaction.

Critics pointed out that this dynamic makes it essentially impossible to shop for clothing reliably online, contributes to return rates, and — in a more philosophical register — embeds a form of self-deception into the routine commerce of everyday life.

Real measurements, posted honestly, would serve consumers better. The incentives run the other direction.