Table 9 presents live-birth rates specific for age of father for as many years as possible between 1990 and 1998.
Description of variables: Age is defined as age at last birthday, that is, the difference between the date of birth and the date of the occurrence of the event, expressed in completed solar years. The age classification used in this table is the following: under 20 years, 5-year age groups through 50-54 years, and 55 years and over.
computation: Live-birth rates specific for age of father are the annual number
of births in each age group (as shown in table 8) per
Since relatively few births occur to fathers of very young or advanced age, rates for men under 20 years are based on all births at ages under 20 but computed on the male population aged 15-19 years. Rates at age 55 and over are based on births at those ages, but computed on the male population aged 55-64 years. The rate for men of “All ages” is based on all live births, irrespective of age of father, but it is computed on the male population aged 15-64 years. This rate for “All ages” is the male equivalent of the general fertility rate that is shown for females in tables 2 and 3. The upper age limit shown here, 64 years, is somewhat higher than the more frequently used limits of 54 or 59 for computing this rate. Births to fathers of unknown age have been distributed proportionately in accordance with births to fathers of known age by the Statistics Division of the United Nations prior to computing the rates.
The populations used in computing the rates are enumerated or estimated distributions of males by age. First priority was given to an acceptable estimate for the mid-point of the year to which the births referred, second priority to census returns of the same year and third priority to an estimate for some other point of time in the year.
Rates presented in this table have been limited to those for countries or areas having at least a total of 100 live births in a given year. Moreover, rates specific for individual sub-categories based on 30 or fewer births are identified by the symbol (g).
Reliability of data: Data from civil registers of live births which 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 data in general, and the information available on the basis of the completeness estimates in particular, see section 4.2 of the Technical Notes.
Limitations: Rates shown in this table are subject to all the same limitations that affect the corresponding frequencies and are set forth in the technical notes for table 8.
With respect to tabulation procedures as a source of non-comparability, the effect of including delayed registrations in the age-of-father birth tabulations may readily be seen in the size of the specific rates for the upper-age span. In some cases high birth rates for age 55 and over may well represent not a measure of fertility at these ages, but the age of the father when the birth was registered.
Births to fathers of unknown age are much more prevalent in age-of-father statistics than they are in age-of-mother distributions, because the characteristics of the father are not collected for illegitimate births. The method of distributing the unknown ages is open to some criticism because of the fact that the age-of-father distribution for legitimate births is known to differ from that for illegitimate births and that the proportion of “unknown ages” is higher among the illegitimate births than it is among legitimate.
The relatively limited coverage of this table as compared to the corresponding table of birth rates by age of mother is due to the fact that a number of countries or areas limit the tabulation of births by age of father to legitimate births only, inasmuch as age is more correctly reported on the latter.
Coverage: Live births by age of father are shown for 67 countries or areas.
Earlier data: Live births by age of father have been shown previously in issues of the Demographic Yearbook featuring natality. For information on years covered, readers should consult the Index.