A tariff announced in one month rarely changes shelf prices in the next. Several buffers sit between the customs payment and the consumer, and each absorbs part of the effect.
Goods already in transit are unaffected
Duty is assessed when goods enter a customs territory, so shipments already cleared were charged under the previous rate and can be sold at existing prices.
Ocean freight takes weeks, and importers frequently accelerate orders ahead of an announced change, building inventory bought at the old rate.
That stockpile must be sold before any tariffed goods reach the shelf, which alone can delay the visible effect by a season.
The cost is shared along the chain
An importer facing higher duty may negotiate a lower price from the supplier, absorb part of the increase in its own margin, and pass on the remainder.
Each participant makes the same calculation, weighing lost volume against lost margin, so the amount reaching the consumer is a fraction of the duty.
Where a product has close substitutes, more of the cost is absorbed upstream, because raising the price would move buyers to an alternative immediately.
Contracts hold prices for a period
Retailers buy under agreements fixing prices for defined terms, and a tariff arriving mid-term cannot be passed on until renegotiation.
Suppliers may invoke clauses covering changes in duties, though invoking them is a commercial decision with consequences for the relationship.
The result is a step change at contract renewal rather than a gradual adjustment, which is why the effect often appears at the start of a buying season.
Sourcing shifts rather than absorbing indefinitely
Where a tariff applies to goods from a specific origin, importers look for suppliers elsewhere, which avoids the duty at the cost of qualification and lead time.
Moving production takes months at minimum and years for complex goods, because tooling, quality approval and logistics must all be rebuilt.
Partial relocation is common, with final assembly moved while components continue to come from the original source, which raises questions about origin rules.
Currency movements can mask the change
Exchange rate shifts alter the local cost of imported goods independently of any duty, and can offset or amplify a tariff entirely by accident.
Because both move at once, separating the effect of a tariff from the effect of currency requires comparing goods that face different duties from the same origin.
This is why estimates of pass-through vary considerably between analyses, and why simple before-and-after price comparisons rarely settle the question.