What it means
An import index describes prices paid for covered foreign supplies, while an export index describes prices received for covered sales abroad, and the basket and methodology determine which transactions the measure represents. An index starts from a reference level and tracks change through time, so a reading of 120 does not mean an average imported item costs $120 or that imports total that amount.
Aggregate movements can hide differences between products, since fuel prices may change sharply while other goods remain stable, making a category-specific series more relevant to a particular purchasing team. The indexes are different from consumer and producer price measures.
They focus on international transactions, so their coverage and pricing basis are not interchangeable with the prices paid by final consumers. Exchange rates can influence trade prices, but the pass-through is not mechanical, because supplier margins, invoicing currency, competition and contract timing can affect how much a currency move changes the price paid.
A company also needs to distinguish an index from landed cost. Import prices exclude duties, and freight, handling and other costs can also affect the final expense.
The BLS methodology pages direct users to concepts, data sources, calculation and programme history, and understanding those definitions helps prevent applying a series to a purchase that it does not represent. New releases may be revised, so comparisons should identify the reference period and series rather than relying on a copied headline with no indication of whether it is preliminary or final.
Trade-price movements can inform inflation analysis and business forecasting. They do not by themselves establish the cause of a company's margin change or the direction of future exchange rates.
For a non-finance manager, the useful approach is to select a relevant category, compare it with actual supplier terms and explain differences. A broad index is a benchmark, not a substitute for the company's own purchasing and sales evidence.
In practice
Real-world examples.
Example
A manufacturer compares a relevant import-price series with its overseas component quotes. Contract terms and product specifications help explain why the two movements differ, and the purchasing team notes the gap in its budget file.
Example
An exporter sees rising prices in its industry's export index. That does not prove it can raise every customer price, because demand and individual contracts still matter.
Example
A manager reads that import prices fell while freight charges rose. The company's landed cost can increase despite the favourable price-index headline, so the budget tracks freight separately.
Formula
Calculation
Percentage change in an index = (new reading / old reading - 1) x 100. State the series and dates being compared.
If a relevant index rises from 125 to 130, the change is (130 / 125 - 1) x 100 = 4%. The five-point increase is not automatically a 5% increase.
A business spending $2 million on a comparable unchanged basket might use $2,000,000 x 4% = $80,000 as a rough price scenario. Different quantities, specifications, currency terms and other costs can make its actual increase different.
The index scenario is therefore a planning input rather than a verified supplier invoice. It should be reconciled with contract evidence before being treated as a committed cost. As a further check, suppose the same business also pays $150,000 of freight and duties that the import index does not capture; its total cost exposure is larger than the index scenario alone suggests.Case study
Seen in the real world.
The following is an illustrative and fictional case. Willow Appliances used a broad import-price headline to forecast the cost of next year's components. The purchasing team found that its main category had moved differently from the aggregate series. Finance also separated component prices from freight, duties and the effects of a new supplier specification. The revised forecast used the category index as a benchmark and supplier quotes for the most important items.
Management kept a range for uncontracted purchases instead of applying one national percentage to every cost line. When the next release revised earlier data, the team recorded the change without rewriting past decisions as though the updated number had been available at the time. Actual purchase results were compared with the assumptions used. The indexes improved the forecast's context. They did not replace product-level information or justify a claim that every imported cost would move in the same direction.
Watch out
Common mistakes.
- Confusing index points with percentage changes or with a currency price per item.
- Applying a broad trade-price index to every company cost without checking category, coverage and landed-cost differences.
- Using a release without identifying the period, series and potential revisions.
Questions
People also ask.
Do these indexes measure trade volume?
No. They measure price change for covered transactions. Volume and total trade value are separate measures.
Is a five-point rise a 5 percent rise?
Only when the starting value makes that true. Calculate the percentage relative to the original index reading.
Can the index replace supplier quotes?
No. It provides a benchmark. Actual prices depend on the items, contracts, currencies and other costs relevant to the business.
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