Education and the contemporary ‘baby boom’: Evidence from the Northern Ireland Longitudinal Study Patrick McGregor Patricia McKee “Predicting Short Run Changes in Fertility in Northern Ireland” a project funded by The authors are grateful to the NILS team at NISRA for their assistance

2 Education and the contemporary ‘baby boom’: Evidence from the Northern Ireland Longitudinal Study Overview Education and fertility The NILS The data The statistical model Results Conclusion

Overview3 A baby-boom fuelled by rising fertility rates and immigration has pushed the population of the United Kingdom to more than 61 million for the first time. The Times, 28 August 2009

4 Total Births Age Specific Fertility Rates Fertility in Northern Ireland

Education and fertility5 Static economic analysis Max ST Children assumed to be normal ‘goods’ so: but possibly or possibly not! The home production framework allows the cost of children to be expressed as a function of the parents’ wages and their respective shares in the costs of producing child quality

Education and fertility6 Dynamic economic analysis The ‘user cost’ of a child now is a function of a sequence of prices such as the female wage rate The optimal profile of a woman’s stock of human capital will be jointly determined with the timing of the births of her children. Any empirical analysis should permit the demographic profile to vary with educational attainment

The NILS7 The NILS potential mothers: those women with health card registrations, aged years and whose DOB is one of the 104 in the systematic sample Registrations downloaded biannually and constitute potential panel members Details of any birth to a NILS mother are forwarded by the GRO to the NILS 2001 Census: An attempt is made to link the Census details of all NILS mothers

The NILS8 Population on Census Day, 2001 Total Population Census 1,685,267 (4.84% Imputed) BSO 1,768,473 (4.94% list inflation) Women in NILS aged years Census 101,034 ( Census x 104/365.25) BSO 107,874 list inflation 6,840 (6.3%) Expected imputed census records 4,890 (101,034 x ) Fertility Panel with census records 93,601 BSO – FP 14,273 Mismatch = 14,273 – 6,840 – 4,890 = 2,543

The data9 Year N % pattern Presence of women in the Fertility Panel: the effect of Age The fertility panel essentially is the 1957 – 77 cohort and ignores the 1978 – 91 cohort due to the absence of educational information

The data10 Sources of Information available for the NILS Fertility Panel 101 Census 91 4,653 7,019 Census 01 GRO BSO 61,263 24,041 32, ,710

The data11 Sources of Parity in the Fertility Panel Parity from Freq. Percent Census - offspring 116, GRO births 10, census 6, Count births Census + n of births Missing 24, Total Women 157,

The data12 Educational Qualifications Level 0 Level 1 Level 2 Level 3 Level 4 Level 5 No qualifications GCSE grade D-G; 1-4 CSEs grade 1; 1-4 ‘O’ level passes; NVQ level 1 5+ CSEs grade 1; 5+ GCSEs grade A-C; 5+ ‘O’ level passes; NVQ level 2 2+ ‘A’ levels; 4+ AS levels; NVQ level 3 or GNVQ Advanced First degree; NVQ level 4; HNC ; HND Higher degree; NVQ level 5

The data13 The Distribution of Educational Attainment

The data14 Source: 2001 Census Distribution of Educational Attainment by Year that Woman was aged 24

The data15 Women in the Labour Market Source: DETINI

The data16 Mean Age of Mother at Time of Birth

The Statistical Model17 The Statistical Model Raftery, AE, Lewis, SM and Aghajanian, A (1995). Demand or Ideation? Evidence from the Iranian Marital Fertility Decline, Demography, vol. 32. Data: 1977 Iran Fertility Survey “ each woman-year of exposure is treated as a separate case” Five clocks: –Age Period Cohort Parity Duration

The Statistical Model18 The Logit Model EDUCATION includes interactions with PARITY, DURATION and TIME so demographic profile can vary with educational attainment TIME captures the change in quantum for women aged > 23

Results19 Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant

Results20 Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant The demographic profile of the base educational category is well determined with parity=0 and durgt5 base

Results21 Work and childbearing tend to be separate rather than combined activities; wage rate not significant although divided by quartiles; interest rate? Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant

Results22 Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant There is a fluctuating increase in the quantum of those 24 and over Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt

Results23 Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant For those from Northern Ireland Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt

Results24 Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant The differential quantum effect of education for those aged >23 in the 1957 – 77 cohort Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt

Results25 Education level01 constant quality timetrend quality*tt Demographic par par par par dur dur dur dur dur durgt Time yr yr yr yr timetrend Economic fwage factivityrate Interest Other catholic constant The differential tempo effect of education for those aged >23 in the 1957 – 77 cohort Demographic age age age age par par par pargt dur dur dur dur dur Demographic interactions agepar agepar agepar agepargt agedur agedur agedur agedur agedur Logit Regression Results Education level 45 constant quality timetrend quality*tt interactions par par par par dur dur dur dur dur durgt

Results26 Marginal Effects Where is the vector of values of all the explanatory variables except for educ For ith woman: Educational variables are ordered: noqual basedegree % sample The marginal effect is taken as the mean of individual marginal effects over the particular category and the base

27 Parity mean par at 24 No quals others Degree Table: Probability of Birth Marginal Effect of Education

Results28 Conclusions The total marginal effect of educational attainment, including both quantum and tempo effects, is almost always positive It peaks at 0.16 for women aged 33 with parity = 1 for the degree case; for parity = 0 the marginal effect is about one third of this In the degree case the quantum effects are negative up to age 28 possibly reflecting the decline in degree ‘quality’ For the poorly qualified the pattern is similar, except that the peak for parity = 1 is earlier, at 30 and smaller, at 0.11 For most ages, the marginal effect is greater for parity 2 than 0

Results29 Parity Proportions by Age and Education

The data30 Births and Birth Events In the analysis birth events rather than births per se are examined