tions
rather than from conversions at official currency exchange rates. The
PPP method involves the use of standardized international dollar price
weights, which are applied to the quantities of final goods and
services produced in a given economy. The data derived from the PPP
method provide the best available starting point for comparisons of
economic strength and well-being between countries. The division of a
GDP estimate in domestic currency by the corresponding PPP estimate in
dollars gives the PPP conversion rate. Whereas PPP estimates for OECD
countries are quite reliable, PPP estimates for developing countries
are often rough approximations. Most of the GDP estimates are based on
extrapolation of PPP numbers published by the UN International
Comparison Program (UNICP) and by Professors Robert Summers and Alan
Heston of the University of Pennsylvania and their colleagues. In
contrast, the currency exchange rate method involves a variety of
international and domestic financial forces that often have little
relation to domestic output. In developing countries with weak
currencies the exchange rate estimate of GDP in dollars is typically
one-fourth to one-half the PPP estimate. Furthermore, exchange rates
may suddenly go up or down by 10% or more because of market forces or
official fiat whereas real output has remained unchanged. On 12
January 1994, for example, the 14 countries of the African Financial
Community (whose currencies are tied to the French franc) devalued
their currencies by 50%. This move, of course, did not cut the real
output of these countries by half. One important caution: the
proportion of, say, defense expenditures as a percentage of GDP in
local currency accounts may differ substantially from the proportion
when GDP accounts are expressed in PPP terms, as, for example, when an
observer tries to estimate the dollar level of Russian or Japanese
military expenditures. Note: the numbers for GDP and other economic
data can not be chained together from successive volumes of the
Factbook because of changes in the US dollar measuring rod, revisions
of data by statistical agencies, use of new or different sources of
information, and changes in national statistical methods and
practices.

GDP - composition by sector: This entry gives the percentage
contribution of agriculture, industry, and services to total GDP.

GDP - per capita: This entry shows GDP on a purchasing power parity
basis divided by