NATIONAL CENTER Series 21 

For HEALTH STATISTICS INumber 12 

DATA FROM THE NATIONAL ViTAL STATISTICS SYSTEM 

Fertility and 

Educational Attainment 

Puerto Rico = 1962 ~l?O!+FW’Y (y~~~ -

An analysis of fertility 

ciated with the educational 

dren born in Puerto Rico 

Washington, D. C. 

U.S. DEPARTMENT OF 

HEALTH, EDUCATION, AND WELFARE


John W. Gardner


Secretary


PUBLICATIONSE3,RANCH 

HIWORIAL M3RARY 

and characteristics of births assoattainment of the parents of chilin 1962. 

September 1967 

Public Health Service 

Wil Iiam H. Stewart 

Surgeon General 
.> 

Public Health Service Publication No. 1000-Series 21-No. 12 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

\Vashington, D. C., 20402- Price cents 
NATIONAL CENTER FOR HEALTH STATISTICS 

FORREST E. LINDER, PH. D., DiTecto? 

THEODORE D. WOOLSEY, Deputy Dzrector


OSWALD K. SAGEN, PH. D., Assistant Director for State Relations


WALT R. SIMMONS, M. A., Sfatisticd Advisor


PHILIP S. LAWRENCE, SC. D., Planning O/ficer


ALICE M. WATERHOUSE, M. D.,Medical Consultant


JAMES E. KELLY, D. D. S., Dental Advisor


LOUIS R. STOLCIS, M. A., Executive O//icer


DONALD GREEN, h/ornration O//icer


DIVISION OF VITAL STATISTICS 

ROBERT D. GROVE, PH.D., Directof 

ANDERS S. LUNDE, PH. D., Assistant Director 

ROBERT A. ISRAEL, M.S., Chic/, Mwfality Statistics Branch 

ARTHUR A. CAMPBELL, Chic/, N@Z2iOJStatistics Branch 

CHARLES R. COUNCIL, Chic/. Registrati’vz Methods Branch 

PATIENCE LAURIAT, Chic/, Muryiwe and DiVO~- s~~tis~ics Byu~C~ 

ALICE M. H ETZEL, Cbie/, Statistical Resources Section 

Public Health Service Publication No. 1000-Series 21-No. 12 

Library of Congress Catalog Card Number 67-60079 
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.’ 

,,. . 

CONTENTS . ,. 

Page 

Introduction -----------------------------------------------:----------

Source -------.---”----

Classificationby EducationalAtWinment


DifferentialFertility --.---- ------. -.-,-------------------- -

Differentials in Age-Specific Fertility ----.-

Differentlals inMarital FertiliW---------------------------:----------

Characteristics Associated With Birth


Season of Birth -.. ,--s----

Marital Status--------------------------------------------------:---

Metropolitan-Nonmetropolitan Residence-------:


Order ofBirth


Birth Weight --------- ----...-,-----------


Su-ary and Conclusions


References


Appendix. Validity of theData


Concep-l Ltiitations


Birth Registration Completeness


PopulationEstimates


Sampling Error-


1 

2 

2 

3 

3 

6 

10 

10 

11 

13 

13 

15 

15 

17 

18 

18 

19 

19 

20 
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CONTENTS—Con. 

Table Page 

1. Age-specific birth rates, byeducation of mother: Puerto Rico, 1962---

2.	 Total fertility rates and their percentage distribution in specified age 

groups, byeducation of mother: Puerto Rico,1962------------------

3.	 Median years from marriage to giving birth, by ageand education of 

mother: Puerto Rico, 1962---------------------------------------

4.	 Estimated median age atlast marriage, by currentage and educationof 

mother: Puerto Rico, 1962---------------------------------------

5.	 Live births to unmarried mothers as apercent of total births, byage 

and education ofmother: Puerto Rico, 1962------------------------

6.	 Live births to married parentsas apercent of total live births, by type 

of marriage and educationof mother and father: Puerto Rico, 1962---

7.	 Percent of all live births to residents of metropolitan areas, by type of 

marriage and education of father: Puerto Rico, 1962 

8.	 Number of live births, median birth order, and percentage distribution 

of live-birth order, by education of father: Puerto Rico, 1962 

9.	 Percentage distribution of live births unselected birth weight classes, 

byeducation of father: Puerto Rico, 1962--------------------------

10.	 Percentage distribution of live births, by birth weight, and median birth 

weight, according to education of father: Puerto Rico, 1962 

2 

4 

9 

9 

11 

12 

13 

14 

16 

16 
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CONTENTS—C on. 

, 

Figure Page 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

Age distribution of women of specified educational attainment 

Age-specific birth rates, by education of mother-------’-------------

Percent of total fe.rtiliq rate in specified age group, by education of 

mother ., -X----­ -.., 

Ratio of total fertility rates by education of mother to total fertility 

rate for women with 13 or more years of school 

Actual and hypothetical numbers of children ever-born per 1,000 evermarried women aged 35-44 years --&--

Mean years of marriage prior to specified order of live birth, by 

education of mother 

Monthly indexes of live births, by, education of mother 

Cumulative percentage of live births of specified order or. higher, by 

education of father 

3 

5 

5 

“7 

7 

8 

10 

1.5 
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IN THIS REPORT statistics ave pwsented and inte’~preted on the education of pavents of children bon?. in Puevto Rico in 1962. 

In 1962, Puevto Rico became the first avea of the United States Bi~th 

Registration System to repovt the educational attainment of pavents on 

the bivth certificate. This Yepovt illustrates the usefulness of such data 

as indexes of socioeconomic statws, to which the fe~tility Yates of the 

motheys and the chavacte?’istics of the newbovn infants are velated. 

With increasing levels of education, the annual fevtility rates Yepovted 

he~e tend to decline, but only among women near the beginningoy the end 

of theiv childbearing peviod. In between, voughiy between the ages of 20 

and 34, b@th Yates are Relatively high foy women of intermediate and 

high levels of educational attainment. The factors associated with this 

high concentration of fevtility of the move highly educated women aye 

(1) a Relatively late age at mawiage, which delays childbearing,, and (2) 

dispyopoytionately few high- ovdey biyths, which, limits feytility in the 

oldey ages. 

Ovdev of, bivth is an impovtant chayactevistic of the newlsoyn inj%nt which 

declines with Yising education of the payents. Othev characteristics 

which aye also found to decline aye immature OYpostmatuve binth 

weight infants and iUe@imacy’. Those chavactevistics ’found to’ incvease with the payents f educational attainment aye Yesidence in a metropolitan a~ea, a ligal as opposed to a consensual foym of rnawiage, and 

the occuwence of the biyth in the iast quaytey of the caienday yeay. The 

medical, psychological, and socioeconomic implications of these Relationships aye discussed. 

Category not applicable . . . 

Quantity zero -

I 

Quantity more than O but less than 0.05---- 0.0 

Figure does not meet standards of 

* reliability or precision 
FERTILITY AND EDUCATIONAL ATTAINMENT


PUERTO RICO, 1962 

Frank H. Godley, Division of Vital Statistics 

INTRODUCTION 

One of the serious gaps in birth statistics 

for the United States is information on the socioeconomic status of the parents. It is accurately 

known how many children are born and the age, 

race, residence, and other characteristics of their 

parents. But no ready index of their socioeconomic 

standing exists. Hence, it is difficult to make 

meaningful statements about the quality of the 

social environment in which children are born 

and raised and to determine how rapidly certain 

important segments of our population are growing. 

To be useful, any index of socioeconomic 

status must be easily stated and defined in essentially the same way in all parts of the country. 

Also, the definition should be the same in both 

vital statistics and the census-based population 

estimates so that valid birth rates may be computed. 

The birth certificates used in most States 

have asked for the occupation of the father, but 

this characteristic has proved to be of little use 

in analyzing fertility statistics. People giving 

information on the birth certificates do not know 

the technical definitions or the terms for many 

occupations. Therefore, it has not been possible 

to relate with acceptable accuracy the information 

entered on the certificates to any standard occupational categories, such as those used “in statistics of the U.S. Bureau of the Census. 

For several reasons, the use of “educational 

attainment of parents” on the birth certificate 

has been proposed as an alternative to “father’s 

occupation” as an index of socioeconomic status. 

A number of recent interview surveys show that 

the parents’ education (most tabulations use that 

of &e mother) is more closely related to fertility 

variables (number of children ever ‘born, spacing 

of births, and effectiveness in controlling pregnancy, for example) than any other single measure 

of socioeconomic status, such as father’s occupation, father’s income, and family income. 

Furthermore, most people know the meaning of 

the standard educational categories (grade school, 

high school, and college) and can report how many 

years they have completed in each. Such reports 

are easy to code and can be directly related to 

the categories of educational attainment used by 

the Bureau of the Census. 

For these reasons, the latest revision of the 

U.S. Standard Certificate of Live Birth (recommended for adoption by all registration areas as 

of January 1, 1968) asks for the educational attainment of the mother and the father and does 

not include any item on father’s occupation. 

Even before it was decided to add educational 

attainment to the standard certificate, two registration areas independently added the item to their 

certificates. Minnesota did so in 1965 and Puerto 

Rico in, 1962. In this report, Puerto Rican data 

for 1962 are used to illustrate the uses of data 

on educational attainment. In the future, it may 

be possible to make similar analyses for the entire United States. 
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Source 

This report is based on registered live births 

in the Commonwealth of Puerto Rico during the 

calendar year of 1962. Births abroad to residents 

of Puerto Rico are excluded. The official livebirth certificates were filed with the Puerto Rico 

Department of Health, Division of Demographic 

Registry and Vital Statistics. Copies were microfilmed and sent to the National Center for Health 

Statistics, where a 50-perce”nt sample of the 

birth records was coded and edited for reporting 

errors. The observed frequencies were then 

doubled for final presentation. 

Classification by Educational Attainment 

Educational attainment is defined as “the 

number of years of school completed. ” The intent 

is to include only those years completed in the 

formal educational system of public schools or 

the equivalent in accredited private schools. The 

educational system of Puerto Rico is structured 

like that of the United States. Grades 1-8 constitute elementary school and grades 9-12, high 

school. Further education, 13 years of school or 

over, represents college. 

The number of years of school completed is 

determined from the following question, asked of 

mothers and fathers, on the birth certificate: 

“t Cual fue el ihtimo grado escolar que complet~?” 

(“What was the last school grade that you completed?”) The answer is recorded by marking one 

of the 14 categories of grades, which are numbered 

singly from O through 13+. 

The replies are classified into six categories 

exclusive of the “unknowns. ” The category “O 

years of school completed” is a rough approximation to those who are totally illiterate, while 

the category ‘‘1-4 years” largely represents the 

functionally illiterate. 1 The balance with an elementary school education are included in the 

group with 5-8 completed years of school. Persons 

with a secondary education are divided into nongraduates (9- 11 years of school) and graduates 

(12 years). One or more completed years of 

Table 1. Age-specific birth rates, by education of mother: Puerto Rico, 1962 

Years of school completed by motherl 

Age of mother 

o 1-4 5-8 9-11 12 13+ Total 

years years years years years years 

Live births per 1,000 women in specified age group 

Total, 15-44 years 2-------- 144.8 153.8 144.9 159.6 137.7 143.8 96.1 

15-19 years 

20-24 years 

25-29 years 

30-34 years 

35-39 years 

40-44 years 

45-49 years 

99.7 155.9 136.8 122.6 81.4 38.5 13.3 

266.9 261,0 284.7 319.9 305.2 237.8 111.8 

192.5 189.7 178.6 206.7 180.5 219,5 174.1 

125.6 155.9 131.6 132.1 109.2 112,4 92.2 

99.1 142.0 112.1 98.7 55.2 54.5 54.6 

40.7 52.6 50.9 36.4 18.1 15.4 12,8 

6.9 11.0 7.3 6.0 4.2 1.3 

1 Rates by education exclude women for whom the number of years of school completed 

was “not stated.” 

2

All live births divided by the female population aged 15-44 years, 

2 
~ ,.5- !9,,.,$ 

m 20-24,’..,s 

m 25-29,.0,s 

~ 30-34,,.,s 

0 I-4 5-8 

YEARs OF SC 

Figure 1. Age distribution of women 

higher education, college, are denoted by the 

group with 13years ormore ofschool completed. 

DIFFERENTIAL FERTILITY 

Differentials in Ag,e-Specific Fertility 

Differences in.family size associated with 

educational attainment have been frequentlynoted 

in puerto Rico.2-7, All evidence points to an 

inverse differential: fewer children are” borne 

by women with more education than by women 

with less education. But these statistics relate 

to numbers of children ever born over a span 

of years. Do similar differentials exist when 

fertility rates are based on children born in a 

single year to women whose ages span the childbea~ing period? 

m 35-3’ ye”” 

m 4.-44,,.,, 

m 

9–II 12 13+ 

HOOL COMPLETED 

of specified educational attainment. 

It is possible that thetwosets of measures 

may show somewhat different, relationships between fertility and educational attainment because 

women in different educational groups space 

their children quite differently over their childbearing years. The extended education. of the 

higher classes, for example, ordinarily postpones 

early marriage and childbearing. It is conceivable 

that when these women begin their families, their 

annual birth rates will be temporarily higher than, 

those for women vzitb less educztion, despite the 

higher ultimate fertility of the latter. 

The general fertility rates (births per 1,000 

women 15-44 years of age) shown in table 1 give 

a misleading impression of educational differences in fertility because the age distributions 

within the age range 15-44 years are quite dif ­

ferent for the educational categories (see fig. 1). 

3 

I 
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In general, proportionately fewer less-educated 

women tend to fall in younger age groups than the 

better-educated women. Hence, the high agespecific fertility rates at the younger ages are 

weighted more heavily for the more-educated 

than for the less-educated women. It is clear, 

therefore, that age-specific fertility rates must 

be examined to avoid distortion due to widely 

different age distributions within the childbearing 

years of life. 

Age-specific birth rates for the education 

groups shown in figure 2 and table 1 give the 

general impression of an inverse relationship. It 

is clear, however, that this is true only within 

certain age groups. (The semilogarithmic scale 

of figure 2 facilitates comparison among the 

widely separated birth rates in the various age 

groups.) In the age groups 20-24 and 25-29 years, 

where the rates are highest and average more 

Table 2. Total fertilitv rates and their 

than 200 births per 1,000 women, class variation 

is small and inconsistent. There is no regular 

decline of the rate with rising education within 

these age groups. In other age groups, however, 

the usual negative fertility differentials are 

found, especially in the extremely young and old 

childbearing age groups, 15-19 and 40-44 years. 

Low rates at the youn~er ages are expected, 

since higher levels of education ordinarily entail 

a postponement of marriage and childbea~ing. 

Low birth rates are also expected for the bettereducated women of the oldest ages, say 35-39 

and 40-44 years, where fertility must be curtailed 

in order to limit family size. 

Table 2 and figure 3 show the relative contribution of each age group to the total fertility 

rate of each educational class. (The total fertility rate is the sum of the age-specific birth 

rates; this gives an unweighed average of agepercentage distribution in specified age 

groups; by education of mother: Puerto Rico, 1962 

Years of school completed by mother 

Age of mother 

Total o 1-4 5-8 9-11 12 ’13+ 

years years years years years years 

I 1 1 I 

Total fertility ratel 

Total, 15-44 years LMl 4,78514,4731 4,5821 3,747/ 3,3911 ”2,293 

Percentage dis~ributi.on 

Total, 15-44 years 100.0 100.0 100.0 100.0 —

100.0 100.0 — 

100.0

15-19 years 

20-24 years 

25-29 years 

30-34 years 

35-39 years 

40-44 years 

12.1 16.3 15.3 13.4 10.9 5.7 2.9 

32.4 27.3 31.8 34.9 40.7 35.1 24.4 

23.3 19.8 20.0 22.6 24.1 32.4 37.9 

15.2 16.3 14.7 14.4 14.6 16.6 20.1 

12.0 14.8 12.5 10.8 7.4 8.0 11.9 

4.9 5.5 5.7 4.0 2.4 2.3 2.8 

lTotal fertility rates are the sums of birth rates by 5-year age group of mother 

multiplied by 5 and are expressed per 1,000 women. 

4

400 

200 

20 

10 ~ 

YEARS OF SCHOOL COMPLETE” 

—. 

by the total fertility rate, the percent of total 

fertility in an age group is equal to the birth 

rate in that age group. This parallel tends to 

break down in the two highest educational groups 

because the unusually high percent-contribution 

to total fertility there of the middle childbearing 

ages 20-34 is more than offset by unusually low 

total fertility rates. The result is relatively low 

age-specific birth rates in these uppermost 

educational groups. 

While this analysis of the distribution of 

fertility over the childbearing ages illuminates 

some irregularities observed in age-specific 

fertility differentials, it should not be taken as 

-%,,,, 20-24 years _ 40 – ,,,,,’ ,,,,,. .- ‘%,,, 

,,,,,,,,,,,,,,., LIS1lI’’’’”” �a,;:


,,,,,,
 ,,,,,,,
 � <;;
 ,,.,, ““’’’’%,, 

*+.#”~ 

20 - .-=*’M 

%,,,,, ,-------- 30-34 years 

%,,,,, 

“’’’%,,,,,,,*, 

10 – G,,,, +, 

:8 –


c1


E


4 

2 

1 

YEARS OF SCHOOL COMPLETE” 

Figure 3. Percent of t9ta T fertil ity rate


in specified age group, by education of


mother.


Figure 2. Age-specific birth rates, by education of mother. 

specific fertility in each educationalclass.)Here, 

the age-specific birth rates within the class are 

expressed as a percentage of their totaL The 

relative contribution of intermediate age groups 

tends to rise with education. The percentage of 

the total fertility rate for each educational class 

for women between the ages of 20 and34 years, 

for example, is 63.4 among women with no schooling, 66.5 among women with 1-4 years of school, 

71.9 among those with 5-8 years, and79-84 among 

those with 9 years or more of school completed 

(see table 2). 

A comparison of figures 2 and 3 shows a 

general tendency for age-specific birth rates to 

follow the pattern of these percentages across 

educational groups. This parallel can be traced 

to a mathematical relationship. When multiplied 

5

an accurate representation of actual timing patterns of childbearing for two fundamental reasons. First’: the data do not refer to the same 

group of women as they proceed through the 

childbearing ages, but rather to a m61ange of 

various cohorts, each observed in only one age 

group. Ideally, reproductive patterns are studied 

by observing the actual fertility of a cohort in 

several age groups. Obviously, the data reported 

here cannot satisfy these ideal conditions. But 

they do represent the beginning of an annual 

series of birth rates by educational class, which 

will eventually make year-by-year cohort analysis possible. (If the youngest age group of Puerto 

Rican women is observed until their fertility is 

completed at ages 40-44, the final year of observation will be 1987. The later adoption ofeducation on the U.S. Standard Certificate of Live 

Birth has extended this date to 1993 for the United 

States.) 

Second, the rates reported here are subject 

to considerable variation from year to year. This, 

too, limits the extent to which they represent 

actual childbearing patterns, A variety of factors 

underlie variation in annual rates. One everpresent factor is reporting error, which may 

affect both the reported number of women giving 

birth and the reported or estimated number in 

the population of a given age-education subgroup. 

A second factor might be termed the variation 

attributed to the particular circumstances of the 

data collection year, 1962. 

On the positive side, annual age-specific 

birth rates for educational classes have the important advantage of recency. Consequently, memory does not affect the number of births per 

women in a calendar year, as it does among women 

reporting on past numbers of children ever born. 

The annual rates also have the advantage of 

referring to the characteristics of the woman at 

the time of her confinement. Consequently, her 

age, parity, length of marriage, place of residence, 

and education, fo; example, can be more accurately used as control variables than would be the 

case among women who have completed their 

childbearing. And last, because they are current 

measures, the annual age-specific birth rates 

include the fertility of women who eventually 

emigrate. This is especially important in Puerto 

Rico because of the large volume of people 

moving to and from the Island. The relatively 

low fertility of women who have emigrated to the 

United States ~ for example, ieaves those with 

substantially higher fertility to report on the 

number of children ever born. 9 Retrospective 

studies may, therefore, exaggerate the actual 

fertility differentials. 

Differentials in Marital FFrtility 

The proportion of women who have ever 

married varies with educational’ attainment in 

Puerto Rico. According to ~he 1960 census, for 

example, among women aged 35-44 years, the 

proportion ever married was 85 percent for those 

with 9 years or more “of school compared with 

91 percent for those with less school. Rates 

based on all women, therefore, exaggerate the 

higher fertility of the less-educated. This is 

shown in figure 4, where the total fertility rate 

for each class is taken as a ratio to that for 

women with 13 years or more of school completed. 

Ratios for all women compared with those for 

married women show the inflation of fertility. 

among the less-educated. ‘ 

Although the educational! differentials in fertility are somewhat less for ever-married women 

than for all women, they ate still substantial. 

This is shown by the total fertility rates for evermarried women in 1962, represented by the solid 

line in figure 5. These rates may be interpreted 

as the average number of births that would occur 

to ever-married women living to the end of the 

childbearing age in a population constantly subject to the age-specific marital fertility rates 

of 1962. (These rates were qomputed by dividing 

the estimated population of women in a given age 

group--whether married or unmarried—into the 

number of births to marrie~ women in the age 

group. To obtain the total fetitility rate for evermarried women, these rates were summed, multiplied by five, and divided by the proportion of 

women aged 35-44 who had ever married, which 

was taken from the 1960 cenqus. ) 

Figure 5 (broken line) also shows the actual 

average number of children ‘ever born, reported 

in the 1960 census by ever-married women aged 

35-44 years (the 1916-25 cohorts, approximately). 

These rates, too, show an inverse relation to 

education, but the range is much greater: 2.3 to 

6.7 children ever born, compared with a range 

of 2.7 to 5.0 for the 1962 hypothetical rates. 

6 
2.50 , 

2.00 *-9. -.*-.----**, Total Women 

* 

* 

$ 

s 

Ever-Married Women 

[.50 

,.oo~ 

o I-4 5-8 9-II 12 

YEARS OF SCHOOL COMPLETED 

Figure 4. Ratio of total fertility rates by 

education of mother to total fertility 

rate for women with 13 or more years of school. 

In the two lowest educational classes, the 

hypothetical rates show the ever-married woman 

eventually bearing 1.5 fewer children than her 

elders actually bore by 1960. Why should this 

be? Twoexplanations arelikely:(l)that completed 

marital fertility of young women, those34 years 

and under in 1962, will eventually declinein the 

lowest educational classes relative to the upper 

(roughly, grade-school versus high-schooleducated women); and (2) that in the lower classes 

young women, unlike those in the up~er classes, 

are not advancing their births to younger ages, 

but upon completing childbearing will nevertheless exceed the fertility of the upper classesby 

the same margin as their eldersdid in1960. 

The first explanation remains a hypothetical 

possibility until the women now under age 34 

complete their childbearing and can be compared 

with older cohorts to see whether ultimate family 

I 

size has in fact decreased among the lower 

classes, while decreasing more slowly (or increasing) among the upper classes. The second 

explanation, that the timing of births only temporarily favors increased fertility of the upper 

educational classes and at ages below 35, is consistent with the finding reported above that the 

concentration of fertility between the ages of 20 

and 35 years tends to reverse the overall inverse 

fertility differentials. As education increases, 

fertility rates for ages 20-34 tend to be increasingly inflated by the concentration of total fertility in these age groups rather than by its overall level. The same appears to hold true for 

married women as for all women. 

Data on the length of the interval between 

marriage and giving birth are also consistent with 

the hypothesis that better-educated Puerto Rican 

\

8 Actual 

8[to womenawd 35-44in 1960) 

;’ 

8 / 

1. 

1“ I I I !-4 ~-~ 9-II 12 

YEARS OF SCHOOL COMPLETED 

Figure 5. Actual and hypothetical numbers


of chi ldren ever-born Der 1.000 ever-mar­


ried women a’ged 35-q~ ~ears~


7 
---- ----- ----------------

women concentrate their births more heavily in 

the intermediate childbearing ages than do the 

less-educated. Table 3 shows that the time between marriage and birth ,declines with rising 

educational attainment for every age group. In 

the group 25-29 years, for example, the years 

from marriage to birth fall from 8,1 to 3.9 as 

education rises. 

How is this reconciled with the relatively 

low total fertility of upper and middle educational 

classes? Shouldn’t they have relatively high total 

fertility if, at each age, birth follows relatively 

soon after marriage? The explanation of this 

paradox lies partly in those wives who did not 

give birth in the calendar year and who, therefore, are not included in the data. Also, part of 

the explanation is that the higher proportion of the 

births to better-educated women are first and 

second births, which follow soon after marriage. 

First, consider the women who do not give 

birth in a given calendar year. The age-specific 

birth rates shown in table 1 suggest that at ages 

35 and above, the proportion of women who did 

not give birth rises with education. It is likely 

that from year to year a considerable proportion 

of women who choose not to have children are 

the same women. These wives are not included 

in the data for length of time between marriage 

and birth. Thus, in a given calendar year, there 

are disproportionately few well-educated women 

becoming mothers long after marriage. 

Second, the. well-educated women who give 

birth in a given year are having disproportionately many first and second births, which generally occur relatively soon after marriage. Figure 

6 shows that the interval between marriage and 

the first birth is nearly the same for all educational groups. Among higher-order births, the 

interval is relatively long for the two highest 

educational classes. Thus, the time between 

marriage and giving birth does not decline with 

education, but the order of birth does. This reconciles the problem, since a decline in order 

of birth implies a limitation of fertility. This is 

consistent with the decline of both fertility and 

the length of time between marriage and giving 

birth. 

Differences in age at the time of last marriage among the women giving birth can be deduced 

from table 3. If, in the age group 25-29 years, for 

[0 

/

/“

,/ e>“+. Fifth births ./ : 

-.-. —. —m-, -

‘-+ / ..$$ 

.$” 

,..” 

*...’ ,,,. Fourth births llll}li!i, !rr,,, t,,,,,,,,,, r,",,,,,,,, r,,, irr#,,,, r,,,ltr,,,,l,,,,,,,,.$' ,,,. 

: 

56 — / a 

m 

< /+ 

z .O+ Il. Third births o =m-*-” N.~. _,_, _,4* / co 

5 

w 

+4 — 

z 

a �+* � 

w *+ z Second births -+++ 

] 

t


0 1 I I I 1’ 

0 I-4 5-8 9-II 1’ 

YEARS OF SCHOOL COMPLETED 

Figure 6. Mean years of marriage prior to


specified order of live birth, by educa­


tion of mother.


example, the mothers are assumed to have a 

median age of 27.5 years, then the median interval 

between marriage and giving birth can be subtracted from this value. The resulting median 

age at marriage is seen to rise with education 

from 19.4 to 23.6 years. Table 4 shows that 

similar median ages at the time of last marriage 

tend to rise with the educational attainment of 

every age group of women giving birth. 

To summarize, proportionately fewer of the 

Puerto Rican women of high educational attainment marry than those of lesser educational 

attainment. Among the married giving birth in a 

particular year, the less-educated have married 

at relatively young ages, have had several children, and as a consequence give the illusion of a 

relatively slow pace of childbearing. The better8


13 
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Table 3. Median years from marriage to giving birth, by age and education of mother:


Puerto lli.co,1962


[Median. are the number of years, to the nearest anniversary, betweerr tbe last marriage of the mother and birth of her child, 

irrespective of birth order. Refers to wives giving bkth during the yeaq 

Years of school completed by mother


Age of mother


o 1-4 5-8 9-11 12 13+ Total


years years years years years years


Total, 15-44 years 4.6 8.9 7.1 “4.4 3.4 3.1 3.7 

15-19 years 2.0 2.2 2.3 2.1 1.9 1.7 1.6 

20-24 years 3.5 5.0 4.5 3.9 3.4 2.4 2.0 

25-29 years 6.1 8.1 7.8 7.1 5.9 4.2 3.9 

30-34 years 10.3 12.1 11.7 10.8 9:1 6.2 6.6 

35-39 years 15.3 15.9 16.2 15.4 12.7 9.3 10.7 

40-44 years 20.3 20.0 21.1 20.6 14.7 14.0 15.6 

Table 4. Estimated median age at	 last marriage, by,current age and educationof mother: 

Puerto Rico, 1962” 

[Refere b wives giving birth during the year] 

Years of school completed by mother


Age of mother


Tota 1 0 1-4 5-8 9-11 12 13+


15-19 years


20-24 years


25-29 years


30-34 years


35-39 years


40-44 years


1


years years years years years years


15.5 15.3 15.2 15.4 15.6 15.8 15.9


19.0 17.5 18.0 18.6 19.1 20.1 20.5


21.4 19.4 19.7 20.4 21.6 23.3 “23.6


22.2 20.4 20.8 21.7 23.4 26.3 25.9


22.2 21.6 21.3 22.1 24.8 28.2 26,8


22.2 22.5 21.4 21.9 27.8 28.5 26.9


Median ag~ at last marriage is the difference between the midpoint of the reported


age group and the reported length of current marriage expressed in years.


9

educated, in contrast, have married at older ages, 

are childless or have borne very few children, 

and as a consequence are having their births 

relatively soon after marriage. Proportionately 

fewer of these better-educated women go on to 

have more children in future years and, consequently, their completed fertility is relatively 

low. 

CHARACTERISTICS 

ASSOCIATED WITH BIRTH 

Education of the parents is related not only 

to annual rates of reproduction, but also to 

characteristics associated with birth. In this 

section, statistics are presented on the seasonal 

variation of births, legitimacy, metropolitannonmetropolitan residence, order of birth, and 

birth weight in relation to educational attainment. 

90 – 

801111111111111 111111111[ II Illllillllll 

JAJO JAJO JAJO 

---7r-- ~ ~ 

Some of the birth characteristics are discussed in relation to the father’s education. As 

the head of the household, the father and his 

level of education are closely related to two 

other major components of socioeconomic status —occupation and family income. Thus, the 

education of the father is a meaningful indicator 

of the socioeconomic environment in which the 

newborn infant begins life. 

Season of Birth 

Births tend to concentrate in the final quarter of the year in Puerto Rico. In a study of the 

season of birth, the maximum incidence of births 

was found to shift from May in 1941-46, to August 

in 1946-50, and to September in 1951-61.10 Data 

for 1952 show this trend toward the last quarter 

to be true in all educational classes, but especially so for mothers in the middle and upper 

educational groups. Figure 7 shows that the 

I 11111111111 11111 !111111 111111111111 

JAJO JAJO JAJO 

~ ~ ~ 

YEARS OF SCHOOL COMPLETED 

Figure 7. Monthly indexes of 1 ive births, by education of mother.


(Ratio of monthly daily average to annual daily average as 100)


10 
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index of births in the final quarter of the year 

is above 110 among mothers with 9 years or 

more of school and about 105 among mothers 

with less school, (The monthly index of birth is 

the ratio of the daily average number of births 

in the given month to the daily average in the 

calendar year. The ratio is multiplied by 100.) 

In order to strike a balance, the upper and 

middle educational classes must have fewer births 

in the earlier months of the year. These deficits, 

too, tend to be more concentrated with advancing 

education, though there are some exceptions. As 

a result, increasing education tends to be associated with an increasing amount of seasonal 

variation. This can be measured by the standard 

deviations of monthly indexes from a mean of 

100. The standard deviation is about 6 in the lowest educational classes, rises to 12 for highschool graduates, and drops back to 7 only in the 

highest class (13 years or more). 

Data for other years are needed to confirm 

the association between education and seasonal 

variation. At present, the association between 

education and the amount of seasonal variation 

in Puerto Rico is opposite that indicated for the 

United States, where the lowest socioeconomic 

groups have the largest amount of seasonal variation.ll The U.S. data, however, are based on 

white-nonwhite and regional comparisons, where 

nonwhite persons and residents of the South were 

found to have unusually large seasonal variation. 

More direct and valid comparisons among socioeconomic groups in the United States and between 

the United States and Puerto Rico will be possible 

when educational data are available from all 

registration areas. 

Marital Status 

There are two types of marriage in Puerto 

Rico. One is legal marriage, in which the couple 

is married formally in a civil or religious ceremony. The other is consensual marriage, in which 

the couple lives together in an informal union 

under common law. Approximately three-fourths 

of all parents of children born in 1962 were 

legally married, while one-fifth were consensually 

married. When added together, both types of 

marriage accounted for 96 of every 100 births. 

This means that about 4 out of every 100 

births were illegitimate. Table 5 shows that 

this percentage varies considerably according to 

the age and educational attainment of the mother. 

Although the percentage of births to unmarried 

mothers declines with age, it also declines with 

educational attainment. 

Table 5. Live births to unmarried mothers as a percent of total births, by age and education of mother: Puerto Rico, 1962 

Years of school completed by mother 

Age of mother 

Total o 1-4 5-8 9-11 12 13+ 

years years years years years years 

Total, 15-44 years 4.1 5.3 4.3 5.2 4.0 2.1 0.8 

15-19 years 

20-24 years 

25-29 years 

30-34 years 

35-39 years 

40-44 years 

7.1 10.4 7.3 7.8 5.6 5.6 3.1 

4.2 6.8 4.7 5.2 4.1 2.3 0.9 

3.1 4.9 3.9 4.1 2.8 1.4 0.8 

2.9 4.9 3.3 3.1 1.7 1.5 1.0 

3.1 3.9 3.1 3.3 3.2 2.0 

2.3 2.6 2.7 2.0 

11

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Table 6. Live births to married parents as a percent of total live births, by type of 

marriage and education of mother and father: Puerto Rico, 1962 

Years of school completed by father 

Type of marriage and 

years of school completed by mother 

Total 0 1-4 5-8 9-11 12 13+ 

years years years years years years 

Married 

Total 95.8 96.6 97.2 96.0 95.7 95.7 97.7 -

O ears 94.7 96.6 96.2 94.6 92.5 87.1 66.7 

l-x years 95*7 97.4 97.7 95.7 94.2 92.7 84.6 

5-8 years 94.8 95.2 96.8 96.1 94.7 92.4 92.1 

9-11 years 96.0 97.1 97.7 96.2 97.2 95.5 93.9 

12 years 97.9 94.7 98.1 98.4 97.3 98.3 98.8 

13+ years 99.2 100.0 100.0 99.1 99.2 99.4 

Legally married 

Total 75.8 65.4 71.1 71.3 77.4 87.1 95.5 

O ears 61.0 64.0 63.3 58.2 58.8 54.8 22.2 

1-{ years 69.5 66.5 73.4 66.8 69.1 74.4 67.3 

5-8 years 72.4 63.7 71.1 73.C 73.4 77.8 85.8 

9-11 years 79.9 70.2 72.6 75.2 81.5 86.1 89.5 

12 years 92.9 78.9 85.7 87.0 89.9 95.2 97.0 

13+ years 98.2 100.0 92.9 97.4 98.2 98.6 

Consensually married 

Total 20.0 31.3 26.1 24.7 18.3 8.6 2.2 

O years 33.7 32.6 32.9 36.4 33.7 32.3 44.4 

1-4 years 26.2 30.9 24.3 28.9 25.1 18.2 17.3 

5-8 years 22.4 31.5 25.7 23.1 21.3 14.6 6.3 

9-11 years 16.1 26.9 25.1 20.9 15.6 9.4 4.4 

12 years 5.0 15.8 12.3 11.4 3.1 

13+ years 1.1 7.1 H 1.0 ::; 

The percentage of births to consensually legitimacy. In the strict legal sense, births in 

married mothers also declines with education. a consensual marriage are just as illegitimate 

Table 6 shows that this is true for the education as those to a never-married mother. The difof the father as well as that of the mother. Be- ference is that the consensual union isdomicililow the ninth-grade level, about linevery3t04 ary (the father lives with the mother and is not 

births occurs to consensually married couples. “just visiting”). As educational levels of the 

Where the husband and wife are of different general population continue torise, more Puerto 

educational levels, the percentage of consensu- Rican women are likely to find the consensual 

ally married diminishes as theeducationofeither union unacceptable andto choose legal marriage. 

spouse rises. Childbearing in a consensual union As a result, illegitimacy should decrease each 

is largely a phenomenon of the lower educational year as it has in the past in Puerto Rico. The 

classes. current percentages of legitimate births by parThis is not surprising since births in con- ents’ educational attainment are shown in table 

sensual unions can be viewed as a form ofil- 6under ’’legally married.” 
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Metro politan-Nonmetropolitan Residence 

Puerto Ricans, like other modernizing people, 

are moving frorm rural to urban areas. One measure of the degree of urbanization is the proportion of the population living in metropolitan areas. 

In 1960, 34,8 percent of the population of Puerto 

Rico lived in one of the three standard metropolitan statistical areas on the Island, Mayaguez, 

Ponce, and San Juan.g Most of the growth of the 

metropolitan population is attributed to migration 

rather than to births. It is therefore appropriate 

to ask in what proportion the newborn are added 

to metropolitan areas and how this varies by 

educational class. 

In 1962 the proportion of births occurring to 

metropolitan residents was 34.2 percent, about 

the same as the percentage of the total population 

living in metropolitan areas. Urbanization, therefore, seems to be more dependent on migration 

than on births. 

Education of the father affects the chances 

nf the newlmrn infant beginning life in a metropolitan area. Fewer than 2 out of 10 children 

born to fathers with no schooling have metropolitan residence, as compared with 6 out of 10 born 

to fathers with some college educatioli. Table 7 

shows that this relationship is stronger for 

legitimate births. In most educational classes, 

consensual marriage reduces class differences 

in the proportion of births occurring in metropolitan areas. 

Order of Birth 

Education of the father is inversely related 

to the birth order of the child. This inverse 

relationship is summarized by the median order 

of birth, which shows that children born to the 

two lowest educational classes were preceded 

by twice as many births as compared with children born to the two highest classes. Table 8 

shows median birth order and the percentage 

distribution of births by order for each educational class of the father. The percentage of 

births in the first three orders declines with 

increasing education. Fourth-order births show 

no relationship to education. Fifth or higher 

order births account for more than 50 percent 

of all live births to fathers in the two lowest 

educational classes, but less than 15 percent 

of the births to fathers in the two highest classes 

(fig. 8), 

The frequency of high-order births in the 

lower educational classes of Puerto Rico adds 

to the economic disadvantages found there. Each 

birth represents a reduction in income for each 

family member, increasing the inequalities of 

gross family income. More frequent sacrifice of 

basic needs in the child’s environment for economic reasons is wel 1 documented in Puerto 

Rico. In ~ 1954 sample survey of the heads of 

1,000 households, the percentage giving “lack of 

economic resources” as the reason for the chiki’s 

leaving school was found to be inversely related 

Table 7. Percent of all live births to residents of metropolitan areas, by type of 

marriage and education of father: Puerto Rico, L962 

[BY mother’s residence in standard metropolitan statistical area] 

Years of school completed by father 

Type of marriage 

Total o 1-4 5-8 9-11 12 13+ 

years years years years years years 

All parental 34.2 17.2 22.6 31.3 40.3 44.2 60.7 

Legally married 34.8 15.1 20.9 30.6 40.3 44.1 61.4 

Consensually married 32.8 22.1 27.0 33.8 42.7 47.2 46.6 

lIncludes married and unmarried parents. 

13 

7 
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Table 8. Number	 of live births, median bi,rth order, and percentage distribution of livebirth order, by education of father: Puerto Rico, 1962 

[Live-birth order refers tQ number of children born alive tQ mother] 

Live-birth order 

Total 

Total 

First births 

Second births 

Third births 

Fourth births 

Fifth births 

Sixth births 

Seventh births 

Eighth births 

Ninth births 

Tenth births and wer----------

Ffedian 

Years of school completed by father 

Total o 1-4 5-8 9-11 12 13+ 

years years years years years years 

Number of live births 

5,3181 18,2781 21,774 112,586 ]11,378[ 6,510 

5! 

Percentage di.stri.bution 

100.0 100.0 100”0 Iw 

22.7 10.3 11.9 

20.3, 10.9 13.0 

15.2 11.7 12.1 

10.1 9.8 10.6 

7.4 9.8 9.4 

5.6 7.7 8.4 

4.5 8.2 7.6 

3.7 8.0 6.2 

2.9 6.2 5.1 

17.1 15.6 

3.51] 5.7! 5.2 

21.7 29.9 31.9 34.4 

20.0 25.8 26.1 28.5 

14.9 1;.: 18.1 19.3 

10.4 9.4 9.7 

7.9 5:5 6.1 4.1 

6.1 3.8 3.4 

4.6 2.3 1.9 ::? 

3.8 2.0 1.2 0.8 

3.0 1.3 0.8 0.2 

7.3 2.4 1.0 0.2 

3.5 2.8 

to the father’s educational Another sample survey 

of 1,000 Puerto Rican families in 1946 linked 

low socioeconomic status with poor housing conditions, poor diets, and poor health practices. 

Low income was associated with theinfant’s not 

being examined by a doctor, ’with dietary deficiencies (especially in high-protein foods), and 

with room-crowding. 2 Medical attention andhospital care, however, do not at present appearto 

favor high socioeconomic position, as Puerto 

Rico’s social medicine program provides drugs 

and hospital and doctor care at littleor no cost 

to those unable to afford the ordinary expense. 

A 1958-59 sample survey of2,951 Puerto Rican 

families found no significant class differences 

in the average number of physician visits or 

hospital stays.12 

Order of birth, in addition to causing a 

reduction in income fov each member of the 

family, may also reduce the emotional support 

that can be given the child. Apart from socioeconomic status, both birth order and size of 

family (which approximates order atthe timeof 

birth) were found to be negatively correlated 

with mental achievement instudies outsidePuerto 

Rico. These findings were re~rted intheintelligence test scores of Swedish males called for 

universal military service at the age of 20.13 

Similar findings were reported for n-year-old 

school children in the 1947 Scottish Mental Survey, which found the relationship between family 

size and intelligence score to hold regardless 

of the mother’s age, reducing the likelihood of 

bias due to incomplete fertility .14 In the United 

States, the first- born are overrepresented among 

the gifted, among the eminent scientists, among 

the National Merit Scholarship Finalists, and 

among college student populations in undergrad14 
Birth order I

“\* \. 

YEARS OF SCHOOL COMPLETED 

Fiaure 8. Cumulative ~ercenta~e of live 

births of specified o;der or-higher, by 

education of father. 

uate, graduate, and professional schools.15 The 

international nature of this evidence suggests 

that birth order may alsobecorrelated negatively 

with educational achievement inPuertoRico. This 

may hinder social mobility by limiting theeducational achievement of children born to lesseducated parents. 

Birth Weight 

Education of the father is associated positively with medium-range birth weights of the 

children, Births in the 2,501-4,500-gram range 

(about 5%’-10pounds) increase from%5.5 percent 

among fathers with no schoolingto 92.7 percent 

among fathers with 13 or more years of school. 

Outside this birth-weight rangethereisa negative 

association between the father’s educationandthe 

relative frequency of births. Table9 shows that 

this is true for both very low and very high 

birth weights. The low extreme (2,500 gramsor 

less) comprises the usual definition ofimmaturity. The percentage of immature births in the 

lowest educational class is 12.1, nearly double that 

found in the highest class. In the upper extreme 

(4,501 grams or more), similar differences are 

found. 

These class differentials are concealed by 

statistics on median birth weight. The median 

birth weight for each educational class is within 

60 grams (2 oz.) of the median for all classes 

combined. Moreover, the medians for 5 of the 6 

groups are within 20 grams (1 oz.) of that for all 

classes combined. Median birth weights and the 

percentage distribution of birth weights in 500-

gram intervals are shown according to the education of the father in table 10. The highest 

relative frequency of immaturity and postmaturity in the lower educational classes implies a 

higher incidence of infant mortality, congenital 

malformation, especially neurological damage, 

and consequent mental retardation. 

SUMMARY AND CONCLUSIONS 

This report illustrates some of the uses of 

data obtained from birth certificates on the educational attainment of parents. Data on births in 

Puerto Rico in 1962 are presented here, but 

similar studies are projected for other birth 

registration areas of tlhe United States. Later 

studies may go well beyond the limits of the present study, especially when data for a series of 

years and different areas become available. 

In this report data on education reported on 

the Puerto Rican birth certificate have been used 

for two purposes: first, to examine the differential 

fertility rates of socioeconomic groups in a calendar year, and, second, to describe differences, 

which are associated with socioeconomic class, 

for characteristics relevant to birth. 

The data indicate certain advantages for those 

children fortunate enough to be born into high 

social classes. The advantages of beginning life 

with a desirable birth weight, few siblings, legally 

married parents, and a metropolitan residence 

favor the newborn infant in the better-educated 

classes. Puerto Rican children beginning life with 

less-educated parents have disproportionately 

high frequencies of immature and postmature 

birth weights, illegitimacy rates, and large numbers of siblings with whom to share the limited 

family resources. 

15

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Table 9. Percentage distribution of live births in selected birth weight classes, by


education of father: Puerto Rico, 1962


Years of school completed by father


Birth weight of child


o 1-4 5-8 9-11 12 13+ Total


years years years years years years


Percentage distribution 

Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 

2,500 grams or less 12.1 10.2 

2,501-4,500 grams 8;:$ 85.5 8?:; 88.0 8;:: 9;:: 9;:; 

4,501 grams and over 1.7 2.4 2.3 1.8 1.2 1.1 1.1 

Table 10. Percentage distribution of live births, by birth weight, and median birth (

weight, according to education of father: Puerto Rico, 1962


Birth weight of child


All births


1,000 grams or less 

1,001-1,500 grams 

1,501-2,000 grams 

2>001-2,500 grams 

2,501-3,000 grams 

3,001-3,500 grams 

3,501-4,000 grams 

4,001-4,500 grams


4,501-5,000 grams


5,001 grams and over


Median, in grams


16


Years of school completed by father


o 1-4 5-8 9-11 12 13+ Total


years years years years years years


Percentage distribution 

100.0 100.0 100.0 100.0 100.0 100.0 100.0 

0.3 0.3 0.2 0.3 0.3 0.2 0.3 

0.6 0.9 0.7 0.6 0.5 0.4 

1.4 1.5 1.6 1.6 M 

;:; 7.5 i ! 

2::; 24.3 23.9 2::; 2::; 2::: 20.4 

37.7 33.7 35.7 37.3 38.9 39.8 42.1 

21.4 21.1 21.6 20.4 20.5 22.6 24.8 

5.7 6.4 5.6 4.8 5.4 5.4 

1.5 H 1.6 1.0 1.0 

0.2 ;:; 0.2 0.1 0.2 0.1 ii’ 

3,210 3,200 3,220 3,190 3,190 3,230 3,270 
The differential rates of reproduction in the 

various educational attainment classes determine 

the size and composition of the cohort being 

born. Of the 1962 Puerto Rican birth cohort, about 

one-third were born to mothers who are functionality illiterate, that is, had completed less than 5 

years of school. Moreover, about one-fifth of the 

newborn infants had both parents at the level of 

functional illiteracy. 

One principal finding in the case of Puerto 

Rico is that when viewed in one calendar year, 

usual negative class fertility differentials may 

be reversed within certain age groups. Fertility 

rates between ages 20 and 29 do not decline with 

education ‘of the mother. This is the result of the 

concentration of fertility in these intermediate 

childbearing years by the better-educated 

mothers. 

A second principal finding is that the annual 

class fertility differentials in Puerto Rico are 

distorted by the age structure of the childbearing 

population.,, Younger generations are attaining 

successively higher educational levels than their 

elders. As a result, less-educated women tend 

to be relatively old, while the better-educated 

are relatively young. These age differences are 

not taken into accoum by the general fertility 

rate, which shows a distorted, pcsitive correlation between educational attainment and fertility. 

Age-adjusted fertility rates are closer to the 

truth and show a negative differential. 

REFERENCES


lTumin, M. M.; Social Class and Social Change in Puerto 

Rico. Princeton, N.J. Princeton University Press, 1961. 

2Stefani, R. L., and Roberts, L. J.: Patterns of Living in 

Puerto Rican Families. Rio Piedras, P.R. University of Puertn 

Rico Press, 1949. 

3Cofresi, E.: Differential fertility in Puerto Rico. Puerto 

Rico J. Pub.HZth Trop.Med. 25(4):460-480, June 1950. 

?Hatt, P. K.: Backgrounds of Hum;n FertiZity in Puetio 

Rico, A Sociological Swvey. Princeton, N.J. Princeton University Prese, 1952. 

5Hill, R., Stycos, J. M., and Back, K. w.: The FamiZY 

and Population Control. Chapel Hill, N.C. University of North 

Carolina Press, 1959. 

6Carleton, R. O.: Labor force participation, a stimulus to 

fertility in Puerto Rico? Demography 2:233-239, 1965. 

7u.s. Bureau of the Census: Fertility by social ard eCOnomic status, for Puerto Rico, 1950. u.S. Census of Population, 1950. Series PC-14, No. 21. Washington. U.S. Government Printing Office, June 24, 1954. 

8u.s. B~eau of the Census: Women by number of children ever born. U.S. Census of Population, 1960. Final Report 

PC(2)- 3A. Washington. U.S. Government Printing Office, Mar. 

1964. table 10, pp. 26-27. 

9u-s. Bureau of the Census: f/,S. census of Popdation, 

1960, Detailed characteristics, PueTto Rico. Final Report 

PC(l)-53D. Washington. U.S. Government Printing Office, 1962. 

table 94, pp. 275-276. 

000 

lcCowgill, U. M.: Recent variations in the season of birth in 

Puerto Rico. Proc.Natn.Acad. Sci.U.S.A. 52:1149-1151, Nov. 

1964. 

llNational Center for Health Statistics: Seasonal variation of births, United States, 1933-63. Vital and Heak% Statistics. PHS Pub. 1000-Series 21-No. 9. Washington. U.S. 

Government Printing Office, May 1966. p. 3. 

12Columbia University School of Public Health and .4dministrative Medicine: Medic ai and Hos pitaz Care in PueTto 

Rico. San Juan. Puerto Rico Department of Health, 1962. 

pp. 3-4. 

13 Quensal, C. T. E.: The interrelations Of marital s~tus, 

fertility, and intelligence test scores. Pop.uZ.Stud. 11(3):234-

250, Mar. 1958. 

14Scottish Council for Research in Education: Sociai Implications of the 1947 Scoti”sh h!entaz Survey. London. University of London Press, 1953. ch. III. 

15Altus, W. D.: Birth order and its sequelae. Science 151 

(3706):4&49, Jan. 7, 1966. 

16National office of Vital S tati sties: Birth registration 

completeness in the United States and geographic areas, 1950, 

part I, data for each State. vitai Stati-sties--Speciaz Reports, 

Vol. 39, No. 2. Public Health Service. Washington, D. C., 

Sept. 21, 1954. p. 43. 

17Vasquez, Jos~ L.: The Apparent worsening in the Registration of BiTths in Puerto Rico. Unpublished paper, University of Puerto Rico School of Medicine, 1963. 

17 
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APPENDIX


VALIDITY OF THE DATA


Conceptual Limitations 

In this report, themost important limitations of the 

data are connected with time and area. The data refer 

to the local area of Puerto Rico in a selected calendar 

year, 1962. Puerto Rico was not selected as representative of class fertility: it is a society neither purely 

Latin American nor Anglo-American, and it is undergoing rapid. social and demographic change. Likewise, 

the calendar year of 1962 was chosen not for typicality, 

but for expediency: 1962 was the first year in which 

education of the parents was included in birth-registration data. It would be hazardous to generalize the class 

relationships observed here to other calendar years 

in Puerto Rico or to other areas. 

Further, using educational attainment as an indicator of socioeconomic status presents two problems. 

First, this indicator is based on one person who may 

not best represent the status of the family. Second, the 

educational attainment of a person does not completely 

describe his socioeconomic status. However, it has been 

shown that educational attainment is highly correlated 

with income and occupational status, providing a convenient summary of how people differ in all of these 

respects. 1 Table I shows that, for both men and women, 

personal income ihcreases with each level in education. 

Likewise, the median educational attainment of Puerto 

Rican men and women increases with each step on the 

income scale. 

Compared with income and occupation as two other 

commonly used indicators of socioeconomic status, 

education has certain advantages. Education has the 

advantage over occupation of being a quantitative variable, and so is simpler to classify in rank order. Education also has the advantage over both occupation and 

income in being relatively fixed for a person’s adult 

life. For some purposes, however, this may be a disadvantage: the educational experience of adults is not 

very recent and, in the case of women completing 

childbearing at age 45, reflects the education completed 

about one-quarter century in the past. Income and occupation are more current indicators of socioeconomic 

status. 

The advantages of an indicator based on education 

become especially apparent when fertility is analyzed. 

Education has been shown in the United States to be 

more closely related to fertility than either income or 

occupation. 15 It represents both the mother and the 

father. And it makes possible meaningful studies of 

illegitimacy by socioeconomic status, since it is 

available for unmarried women. 

A final advantage of education is the high quality 

of the statistics. Education has been especially well 

reported in Puerto Rico. Of the 153,192 parents of liveborn infants in 1962, only 1,094 or less than 1 percent 

failed to report their education on the birth certificate. 

In view of this excellent reporting and the facility with 

which it is processed, education has been on balance 

the best socioeconomic indicator ever used on birth 

certificates. 

Table I. Median income in 1959 of persons 25 

yeara and ove~, by years of school- completed 

and sex: Puerto Rico, 1960 

Years of school completed 

O years ------p-- -

1 and 2 years 

3 and 4 yeara 

5-7 yeara 

8 years 

9-11 years 

12 yeara 

13-15 years 

16+ yeafa 

5 

Median 

income 

in dollars 

472 180 

690 287 

805 344 

1,120 540 

1,593 846 

1,813 1,176 

2,299 1,726 

2,746 2,026 

5,510 2,763 

SOURCE: U.S. Bureau of the Cenaua,U.S. Cenaua 

of Population, 1960, Detailed Characteristics, 

Puerto Rico.Final Report PC(1) -53D. Washington, 

Us. Government Printing Office, 1962, table 

117, pp. 54-387. 

18 
--------------

---------------------------

Birth Registration Completeness 

Puerto Rico was admitted to the birth registration 

area of the United States in 1943, which means that 

registration was at least 90 percent complete in that 

year. It was 86.5 percent complete j~ i940 according 

to the U.S. Birth Registration Completeness Test. 

Studies of matched infant records and live birth certificates indicate a birth registration completeness of 95 

to 96 percent in the 1950’s.16,17 However, an inherent 

bias of these test methods fails to count the unregistered 

births of infants for whom an infant record is also 

missing. High rates of infant emigration, underenumeration, and death underregistration make this a serious 

bias in Puerto Rico as compared with the United States. 

When this was taken into account, slightly lower levels 

of birth registration completeness have been estimated 

for Puerto Rico in recent years. 

For the year of, this report, 1962, a representative 

sample of hospitals (hospital births accounting for 82.3 

percent of the total) showed registration to be 94.1 percent complete,L7 Since registration of births occurring 

outside of hospitals is ordinarily less complete, the 

Island-wide figure may be below 94 percent. The completeness of birth data shown in this <eport is therefore 

judged to be in the range of 90-94 percent. 

Population Estimates 

The fertility rates presented in this report for the 

calendar year of 1962 are based on estimates of the 

midyear population of Puerto Rican women by age and 

educational attainmen~ The estimating procedure was 

the following 

1.	 The number of women and men in 5-year age 

groups, from 15 to 49 years, was estimated as 

of July 1, 1962. Here is made the only allowance 

for mortality and migration (i.e., variation in 

these components by education was not considered); these age-sex estimates were prepared by the Puerto Rico Bureau of Demographic Registry and Vital Statistics for its 

Annual Vital Statistics Report, 1962. 

2.	 Educational attainment in 1962 was estimated 

by advancing age cohorts from April 1960, when 

education was reported in the census; different 

techniques were used for the cohorts under age 

23 and those aged 23 and older, as described 

below. 

3.	 Cohorts aged 23 and older were assumed to have 

completed their education at the time of the 

Table 11. Estimated. female population, by age	 and years of school completed: Puerto Rico, July 1, 

1962 

Years of school cotapleted 

Age 

Totall o 1-4 5-8 9-11 12 13+ Not 

years years years years years years stated 

Number in thousands 

Total, 15-49 years 586.8 58.5 151.5 169.6 89.1 66.7 50.2 1.9 — — — — — — — — 

15-19 years 127.8 3.3 16.7 49.6 39.4 14.0 4.8 0.0 

20-24 years--------------------------- 98.2 5.9 17.6 27.0 17.0 18.2 12.5 0.0 

25-29 years--------------------------- 89.7 8.0 22.8 22.7 11.8 13.3 10.7 0.4 

30-34 years--------------------------- 81.7 8.8 24.6 20.7 8.8 9.4 9.1 0.3 

35-39 years--------------------------- 70.7 10.0 24.6 18.8 5.6 5.4 6.1 0.2 

40-44 years--------------------------- 60.9 10.1 22.9 16.4 3.6 3.6 4.1 0.2 

45-49 vears--------------------------- 57.8 12.2 22.3 14.4 2.9 2.8 3.0 0.2 

1 Puerto Rico Division of Demographic Registry and Vital Statistics, Annual Vital Statistics 

Report, 1962, p.3. 

19 
4. 

5. 

6. 

1960 census. Inthenext2 years, the two eldest 

ages of a 5-year group entered the next higher 

age group, while ,the other three remained in the 

original 5-year group. This relationship was 

used to extrapolate the 1962 educational attainment of a 5-year age group. Three-fifths was 

represented by the same age group, and twofifths by the next younger age group. 

For cohorts aged 23 years and younger in 1960, 

the education attained between April 1960 and 

July 1, 1962, was taken into account. The 

procedure used for grades l-12andfor13years 

or more of school completed, differed as described below. 

For grades 1-12, official school enrollment and 

promotion rates were applied by single grade of 

school and single’ year of age, starting with the 

1960 census populations; the revised cohort 

populations at each educational level were 

carried forward to mid-1962. 

A result of the above step was the category “12 

years or more of school completed. ” This was 

split into 12 years and 13 years or more of 

school, by age, in accordance with the proportions stated at those ages in the 1960 census. 

(The lack of higher education enrollment and 

completion data by age and sex did not permit 

direct increases in the cohort populations at the 

13 years or more of school completed level.) 

000 

7.	 Grouped into 5-year age categories, the resulting mid: 1962 population estimates were adjusted to equal the control totals by age and sex. 

we differences were distributed in proportion 

to the frequency estimated at each educational 

level. Table II shows these final population estimates. 

Sampling Error 

Sampling errors apply both to the number of births 

and to the population bases on which fertility rates 

were calculated. The fraction of birth records sampled 

was 50 percent. The fraction of population (household) 

records sampled was 25 percent, every fourth household being systematically included inthe sample which 

was questioned about education. In this way, suchcharacteristics as educational attainment are assumedtobe 

selected at random in both samples. 

In most instances the sampling error of birth frequencies in this report is negligible. However, for frequencies of 100 or fewer births, the sampling error is 

likely to deviate above 10 percent. 

Fertility rates have a slightly higher sampling error 

than that of the births on which they are based. The 

standard error of a fertility rate is approximately the 

square root of the sum of the squares of (1) the standard 

error of the number of births and(2) the standard error 

of the population base. Sampling error (2) may be 

expected to affect the population estimates in this report 

by no more than 5 percent and hence is often negligible. 

20 
OUTLINE OF REPORT SERIES FOR VITAL AND HEALTH Statistics 

Public Health Service Publication No. 1000 

Series 1.	 PYo.grams and collection pYoceduYes.— Reports which describe the general programs of the National 

Center for Health Statistics and its ofEices and divisions, data collection methods used, definitions, 

and other material necessary for understand@g the data. 

Se7+es 2.	 Data evaluation and methods YeseaYch. —Studies of new statistical methodology including experimental tests of new survey methods, studies of vital statistics collection methods, new analytical 

techniques, objective evaluations of reliability of collected data, contributions to statistical theory. 

SeYies 3,	 Analytical studies. —Reports presenting analytical or interpretive studies based on vital and health 

statistics, carrying the analysis further than the expository types of reports in the other series. 

Sevies 4. Documents and committee YepoYts. —Final reports of major committees concerned with vital and 

health statistics, and documents such as recommended model vital registration Iaws and revised birth 

and death certificates. 

Series 10.	 Data from the Health Interview Swvey. —Statistics on illness, accidental injuries, disability, use of 

hospital, medical, dental, and other services, and other health-related topics, based on data collected 

in a continuing national household interview survey. 

Series 11.	 Data jj-om the Health Examination Swvey. — Data from direct examination, testing, and measurement of national samples of the population provide the basis for two types of reports: (1) estimates 

of the medically defined prevalence of specific diseases in the United States and the distributions of 

the population with respect to physical, physiological, and psychological characteristics; and (2) 

analysis of relationships among the various measurements without reference to an explicit finite 

universe of persons. 

Sevies 12.	 Data f.vonz the In.stitutiond Population SuYveys.— Statistics relating to the health characteristics of 

persons in institutions, and on medical, nursing, and personal care received, based on national 

samples of establishments providing these services and samples of the residents or patients. 

SeTies 13. Data @om the Hospital DischaYge Survey. —Statistics relating to discharged patients in short-stay 

hospitals, based on a sample of patient records in a national sample of hospitals. 

SeTies 20.	 Data on moYtality.—Various statistics on mortality other than as included in annual or monthly 

reports —special analyses by cause of death, age, and other demographic variables, also geographic 

and time series analyses. 

Series 21.	 Data on natality, man-iage, anddivoyce. —Various statistics on natality, marriage, and divorce other 

than as included in annual or monthly reports— special analyses by demographic variables, also 

geographic and time series analyses, studies of fertility. 

SeYies 22.	 Data porn the National Natality and MoYtality Szwveys. —Statistics on characteristics of births and 

deaths not available from the vital records, based on sample surveys stemming from these records, 

including such topics as mortality by socioeconomic class, medical experience in the last year of 

life, characteristics of pregnancy, etc. 

For a list of titles of reports published in these series, write to: Office of Information 

National Center for Health Statistics 

U.S. Public Health Service 

Washington, D.C. 20201