Replacing a zip can cost more than buying a new jacket. This is not a market failure but the predictable result of comparing local skilled labour against globalised manufacturing.
Repair is priced in local hours
A repair happens where the customer is. The alteration hand works one garment at a time, and the time cannot be compressed by scale because every job is different.
New garments are made in long runs by operators each doing one operation repeatedly, in countries chosen partly for labour cost, with the work split into short standardised steps.
The comparison therefore sets an hour of skilled local labour against a few minutes of divided offshore labour, and the arithmetic goes one way.
Disassembly has no factory equivalent
Manufacturing runs in one direction. Pieces are joined in a fixed sequence and every operation assumes the previous one is complete.
A repair reverses part of that sequence. Unpicking a lining to reach a zip tape, working around a bar tack, then rebuilding what was opened takes longer than the original assembly did.
No equipment exists to speed this up, because factories never need to do it, so repair remains stubbornly manual in a way production does not.
Construction choices make repair harder
Overlocked seams with no allowance cannot be let out. Bonded hems have no stitching to unpick. Fused interfacings cannot be lifted without damaging the face fabric.
These methods are chosen because they are fast and cheap, and repairability is not a design criterion in most price brackets.
A garment built to be repaired costs more to make, which puts the durable option at a disadvantage at the point of sale even though it wins over a longer horizon.
The trade base has thinned
Alteration skills used to be widespread because clothing was expensive relative to income and repair was routine. Demand supported a large number of practitioners.
As clothing prices fell, demand fell with them, apprenticeships dried up and the remaining specialists became scarcer and correspondingly more expensive.
Scarcity feeds back into the price, which suppresses demand further, and the loop has been running in the same direction for several decades.
Where the maths still favours repair
Repair wins on garments where the replacement is genuinely expensive, such as tailoring, outerwear, leather goods and knitwear in good fibres.
It also wins where fit is the value. A jacket altered to fit properly is worth more to its owner than an unaltered replacement at the same price.
The category where repair loses is the one it is most often urged for, namely cheap garments, where nothing about the economics supports the argument being made.