Table
14
Table 14
presents legitimate live births by duration of married life for as many years as
possible between 1990 and 1998.
Description
of variables: Legitimate refers to persons born of parents who were married at
the time of the birth in accordance with the laws of the country or area.
Births of unknown legitimacy status are assumed to be illegitimate and are
excluded from distributions.
Duration
of married life is the number of completed years elapsed between the exact dates
of first marriage of the wife and the exact date of birth of the child. Although this table in principle shows
births by total duration of married life, statistics for many countries or areas
are tabulated in terms of duration of current marriage only, which is defined as
the number of completed years elapsed between the exact date of current marriage
and the exact date of birth of the child. This differs from duration of married
life when the wife has been married more than once. Except where otherwise indicated, 14
categories are used to classify duration (in years): under 1 year, single years
from 1 to 9 inclusive, 10-14, 15-19, 20 and over and unknown.
Reliability
of data: Data from civil registers of live births that are reported as
incomplete (less than 90 per cent completeness) or of unknown completeness are
considered unreliable and are set in italics rather than in roman type. Table 1 and the technical notes for that
table provide more detailed information on the completeness of live birth
registration. For more information
about the quality of vital statistics in general, and the information available
on the basis of the completeness estimates in particular, see section 4.2 of the
Technical Notes.
Limitations:
Statistics on legitimate live births by duration of married life are subject to
the same qualifications which have been set forth for vital statistics in
general and birth statistics in particular as discussed in section 4 of the
Technical Notes.
The
reliability of data, an indication of which is described in the above paragraph,
is a very important factor in considering the limitations. In addition, some
live births are tabulated by date of registration and not by date of occurrence,
these have been indicated by a (+).
Whenever the lag between the date of occurrence and date of registration
is prolonged and, therefore a large proportion of the live-birth registrations
are delayed, birth statistics for any given year may be seriously affected.
Another
factor that limits international comparability is the practice of some countries
or areas not to include in live-birth statistics infants who were born alive but
died before registration or within the first 24 hours of live, thus
underestimating the total number of live births. Statistics of this type are
footnoted.
Variations in the national definitions of
“legitimate” on which the data are based contribute on important element to
non-comparability. Among countries
and areas the legal basis for establishing legitimacy differs, including the
types of union that establish legitimacy.
For detail discussion of these factors, see the technical notes for table
13.
A major
source of non-comparability of the data in this table is that some countries or
areas have tabulated legitimate live births in terms of total duration of
married life and others in terms of duration of current marriage. As has been noted above, the two
concepts are not the same when the wife has been married more than once. To the extent possible, all data in this
table have been footnoted indicating whether they are based on total duration of
married life or duration of current marriage.
The
effect of these two methods of defining duration is that, for women married more
than once, a birth occurring early in the second marriage would be shown as
occurring in a higher-duration category using a duration of married life concept
than it would be if the same birth were classified in terms of current marriage
concepts. The greater the
difference in time between date of first marriage and date of current marriage,
the greater the potential impact of this source of
non-comparability.
Coverage:
Legitimate live births by duration of married life are shown for 51 countries or
areas.
Earlier
data: Legitimate
live births by duration of married life have
been shown previously in issues of the Demographic Yearbook featuring
natality. For information on years
covered, readers should consult the Index.