account balance, because the dollar values presented in the
Factbook for these items have been converted at official exchange
rates, not at PPP. One should use the OER GDP figure to calculate the
proportion of, say, Chinese defense expenditures in GDP, because that
share will be the same as one calculated in local currency units.
Comparison of OER GDP with PPP GDP may also indicate whether a currency
is over- or under-valued. If OER GDP is smaller than PPP GDP, the
official exchange rate may be undervalued, and vice versa. However,
there is no strong historical evidence that market exchange rates move
in the direction implied by the PPP rate, at least not in the short- or
medium-term. Note: the numbers for GDP and other economic data should
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.

GNP: Gross national product (GNP) is the value of all final goods and
services produced within a nation in a given year, plus income earned
by its citizens abroad, minus income earned by foreigners from domestic
production. The Factbook, following current practice, uses GDP rather
than GNP to measure national production. However, the user must realize
that in certain countries net remittances from citizens working abroad
may be important to national well-being.

GWP: This entry gives the gross world product (GWP) or aggregate value
of all final goods and services produced worldwide in a given year.

Geographic coordinates: This entry includes rounded latitude and
longitude figures for the purpose of finding the approximate geographic
center of an entity and is based on the Gazetteer of Conventional
Names, Third Edition, August 1988, US Board on Geographic Names and on
other sources.

Geographic names: This information is presented in Appendix F: Cross-
Reference List of Geographic Names. It includes a listing of various
alternate names, former names, local names, and regional names
referenced to one or more related Factbook entries. Spellings are
normally, but not always, those approved by the US Board on Geographic
Names (BGN). Alternate names and additional information are included in
parentheses.

Geography: This category includes the entries dealing with the natural
environment and the effects of human activ