1957 - United Nations Statistics Division

Since the way in which cities are delimited differs from
country to country, efforts have been made to include in
the table not only data for the so-called "city proper"
but also those for the "urban agglomeration" if such
exists. The urban agglomeration has been defined as including
the suburban fringe or thickly settled territory
lying outside of, but adjacent to, ihe city boundaries.
Whenever an "urban agglomeration" figure is available,
it has been used as the basis for applying the 100,000
criterion in order that every "city" of the selected size
class, however defined, may be included.
Except for the capital city, which is listed first irrespective
of size, the order of presentation in Table 5 is
by population size of city proper, the largest being given
first. This method was chosen because more countries
have data for the "city proper" than have urban-agglomeration
estimates. It means, however, that the "agglomerations",
when available, may not be in strict population-size
order.
In respect of language, the city names have been shown
in the language of the country to which they pertain or,
if required, in a transliteration of it. Hence, cities in
English- or French-speaking countries are listed in either
of those languages as reported, without translation. These
principles of presentation were adopted because of the
difficulty of establishing English and/or French equivalents
for official names of cities.
Coverage: Cities for a total of 184 countries and territories
are included in Table 5. Of these, 109 are the capital city
only, indicating that no other city in that country has as
many as 100,000 inhabitants. According to Table 5, cities
of 100,000 or more number 1034, but this should not be
considered the world total for cities of this size because,
as may easily be observed, data have not been made available
for many countries in which cities of this size may be
presumed to exist.
For purposes of the Demographic Yearbook) vital statistics
have been defined as statistics of live birth, death,
foetal death, marriage, and divorce. This is in accord with
Principle 201 of the United Natio'1s Principles for a
Vital Statistics System 16 which defines the field of vital
statistics as encompassing these, as well as statistics of
adoptions, legitimations, recognitions, annulments, and
legal separations.
Actually, the factors affecting international comparability
of vital statistics are much the same as those which
determine the variation in population statistics. Differences
in geographic and ethnic coverage of the data;
variation in completeness of the statistics, i.e., in completeness
of registration; diverse tabulation procedures;
and differences in statistical definitions of vital events all
may influence comparability.
Standards for improvement of vital statistics in respect
of these factors and others have been set forth by the
United Nations in the Principles for a Vital Statistics
16 United Nations. Statistical Office. Principles for a Vital Statistics
System; Recommendations for the hnp"ovement and Standardization
of Vital Statistics. Document ST/STAT/SER.MjI9, 26 August
1953, p. 6. (Sales No. 1953XVll.8)
17 Ibid.
VITAL STATISTICS
23
Limitations: City popUlations are especially affected by the
difficulties of defining the de facto and de jure concepts
in relation to them. Comparability is also impaired by
different methods used in constructing the estimates and
by the lack of precision which may be present even in the
same methods. For example, births and deaths occurring
in the cities do not all originate in the popUlation present
in, or resident of, that area. Therefore, the use of natural
increase to estimate the probable size of the population is
often the source of large errors. Internal migration is a
second estimating component which cannot be measured
with accuracy in many areas. Because of these factors,
data in Table 5 are of limited value for international
comparisons.
Comparability is even more limited by variations in
the national concepts used to define a "city" for administrative
purposes. In some countries, "cities" are localities
with fixed boundaries and an administratively recognized
"urban" status which is usually characterized by
some form of local government. In others, e.g., Japan,
the "city proper" is an administrative division composed
of a major agglomeration and adjoining territory which
may either be distinctly rural in character or which may
contain other quite separate agglomerations. Whenever
it was known that the data referred to the latter type,
they have been noted in the table, but even with these
warnings, comparisons based on "population size" must
be made with extreme caution.
Finally, it must be mentioned that data in Table 5 are
the latest available for each country. They may have
been obtained from city censuses, as in Liberia, from
national censuses, from regular estimating procedures, or
from ad hoc surveys. Their reference dates tend to be
diverse in any case, and inasmuch as city populations
tollow all types of growth patterns, comparison between
data for different years is usually not valid.
System,17 These recommendations for improvement and
standardization of vital statistics were adopted by the
United Nations Statistical Commission at its seventh session
in February 1953. They were subsequently approved
by the Economic and Social Council at its fifteenth session
in April 1953 under Resolution 469 D (XV) and, with
the adoption by the General Assembly of the Council's
Report, became United Nations recommendations.
To enhance the utility of the Principles and to assist
in their application to national situations, a Handbook of
Vital Statistics Methods 18 has been prepared. The Handbook
also discusses in detail the possible sources of error
in vital statistics, which will be outlined below.
SOURCES OF VARIATION
Coverage-geographic and ethnic
Despite the fact that live births, deaths, foetal deaths,
marriages, and divorces have been recommended by the
United Nations as meriting priority in registration and
reporting, the availability of statistics on these events
18 United Nations. Statistical Office. Handbook of Vital Statistics
Methods. Document STjSTATjSER.Fj. April 1955, 258 p. (Sales
No. 1955.XVll.l)