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Using the Cohort Studies: Understanding the postponement of parenthood to later ages

Ann Berrington

ESRC Centre for Population Change

University of Southampton, UK

5th ESRC Research Methods Festival 2-5th July, 2012

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Motivation: UK Context

• TrendsRelative high fertility: TFR~1.9, CFS~1.9

Persistently high teenage parenthood in context of increasing mean age at first birth

Social polarisation of childbearing

• Explanations from literature Higher education

Labour force participation of women

Economic uncertainty

Ideational change

Partnership dynamics as a proximate determinant

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Research Questions

1. How have the predictors of fertility postponement changed across cohorts?– Education – Partnership status

2. What factors are associated with the recuperation of fertility? How have these changed across cohorts?– Fertility intentions– Economic uncertainty– Partnership status

Sample design of 1958 and 1970 birth cohorts

  Age at which interviews completed

1958 cohort (NCDS)

0 7 11 16 23 33 42 46 50

 1970 cohort (BCS)

0 5 10 16 30 34 38 42  

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Analytical framework

Childbearing patternsParental socio-demographic background

Childhood experiences

Partnership trajectories

Employment trajectories

Age

Historical time

Fertility intentions

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Methods: Discrete time event history analysis of conception leading to first birth

• Monthly indicator of a conception occurrence

• Parental background • Childhood indicators • Educational enrolment (time-varying) and attainment

(time-varying)• Partnership status (time-varying)• Plus fixed covariates measured at age 33/30

– Intentions– Economic activity status

01|1Pr tytyth jjj

ty j

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Some findings on postponement (1/4)

Percentage females who had a child by age 30 according to father’s social class, 1958 and 1970 cohorts

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Some findings on postponement (2/4)

Percentage of those childless at age 30 who intended to become a parent according to educational qualification

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Some findings on postponement (3/4)

% achieved at least one child by age 38

Men Women

Intended to have a child

57.7 62.9

Uncertain 35.8 38.7

Did not intend to have a child

14.6 21.5

Percentage 1970 cohort who achieved a birth according to childbearing intentions at age 30

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Some findings on postponement (4/4) The role of economic uncertainty

• Discrete time hazards model of monthly probability of first birth after age 30Model 1: Unadjusted

Model 2: plus parental and childhood characteristics, education, economic activity, socio-economic group

Model 3: plus childbearing intentions

Model 4: plus partnership status

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1970 cohort: Odds ratios for first birth between exact age 30 and exact age 38 by economic activity

Model 1

unadjusted

Model 2

+ socio-economic

Model 3

+ intentions

Model 4

+ partner status

Males FT employee 1 1 1 1

FT self employed 1.00 1.00 0.96 1.09

Part time 0.46** 0.48** 0.48** 0.73

Unemployed 0.43*** 0.45*** 0.45*** 0.96

Sick / disabled 0.30*** 0.34*** 0.41** 1.04

Other 0.56** 0.58* 0.57* 1.00

Females FT employee 1 1 1 1

FT self employed 1.12 1.08 1.06 1.12

Part time 0.70** 0.73** 0.76* 0.73**

Unemployed 0.47*** 0.50* 0.48** 0.84

Sick / disabled 0.42*** 0.43** 0.52 0.76

Other 0.70* 0.73 0.78 0.81

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Some conclusions (1/2)

• 1970 birth cohort experienced strong postponement but also significant recuperation– Increased social polarisation

• Effect of partnership status on risks of conception leading to first birth is stable over time and is similar for men and women– But 1958 cohort more likely to marry before the actual birth.

• Educational enrolment – Effect especially strong for younger cohort

• Among those who remain childless in their thirties, more educated men and women have more positive intentions to childbearing

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Some conclusions (2/2)

• There is a considerable amount of uncertainty in intentions, particularly among highly qualified women– Role conflicts

• Unfulfilled childbearing intentions– Suggest significant barriers to fertility remain for some

• Residual group of socio-economically disadvantaged individuals (particularly men) find it difficult to form a co-residential partnership and thus make the transition to parenthood.– Note 1990s recession – impacted on recuperation of births for

1958 cohort and postponement of births 1970 cohort

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Further information

For more information see:

Berrington and Pattaro (2011) The Recuperation of Fertility at Older Ages: A Cross-Cohort Comparison of the Role of Education, Fertility Intentions and Partnership Careers.

http://www.cpc.ac.uk/research_programme/?link=postponement.php

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Acknowledgements

This research is funded by the Economic and Social Research Council (Grant number RES-625-28-0001).

Serena Pattaro helped derive the data and undertake some of the analyses.

The National Child Development Study is maintained and developed by the Centre for Longitudinal Studies, Institute of Education, University of London and was made available via the Data Archive.

We thank staff at the Centre for Longitudinal Studies for their help in answering various queries relating to the data and for their help in cleaning the partnership histories.