Revisions to the Components of the Trade Balance for the United Kingdom.

It is well known that the time series of the components of the trade balance undergo substantial revisions. This note summarizes the magnitude of revisions to appropriately scaled versions of the current price series for the exports of goods, the exports of services, the imports of goods, and the imports of services. The revisions are proportionately greatest for the services series with, for example, maximum positive revisions of +18.5 percent and +15.3 percent for the exports and imports series, respectively. The statistical evidence suggests the possibility of a structural break in the revisions process around 1977 for the exports of goods and imports of goods series; and, in the later period, the author cannot reject the hypothesis of unbiasedness for these two series. However, the author does firmly reject this hypothesis for the two services series. A fairly simple bias correction could be applied.to the biased series. Copyright 1992 by Blackwell Publishing Ltd