||Price in a given currency at which bills drawn in another currency may be
bought (9). Exchange rates are classified by IMF into three broad categories,
reflecting both the role of the authorities in the determination of the
exchange rates and/or the multiplicity of exchange rates in a country. The
descriptor market rate is used to describe exchange rates determined largely by
market forces; the official rate is an exchange rate determined by the
authorities, sometimes in a flexible manner. For countries maintaining
multiple exchange arrangements, the third category, the rates are labeled
principal rate, secondary rate and tertiary rate.
For the period average rates, the data are either the monthly average of market
rates or of official rates of the reporting country, or, if those are not
available, monthly average rates in New York, or, if those are not available,
estimates derived on the basis of a simple average of the end-of-month market
rates in the markets of the reporting country. (16, Introduction, sect. 1)
||Oxford University Press (1982). The Concise Oxford Dictionary of Current
English, Seventh Edition (London).
International Monetary Fund (IMF, annual). International Financial Statistics
Yearbook. (Washington, D.C.).