Though not a market-moving release, export/import prices are a useful indication of inflation pressures created by changes in foreign exchange rates. For example, when the dollar is strong, import prices tend to be under downward pressure. If an item in Japan costs 500 yen and the exchange rate is 100 yen to the dollar, the US$ price $5. If the dollar then strengthens to Y120, the US$ price falls to $4.17. Because US exports must compete with foreign goods, there is also downward pressure on export prices when the dollar is strong.
Economists typically look at import prices excluding oil and export prices
excluding agricultural. In each case, the category in question is excluded
because prices for those items are volatile and the swings are unrelated to
foreign exchange rates. Oil prices tend to swing in response to OPEC decisions,
and agricultural prices are often affected by weather, neither of which say much
about long-term trends in traded goods prices.