Does Mothers’ Employment conflict with Child
Development?
Multi-level analysis of British mothers born in 1958
Heather Joshi
co-author Georgia Verropoulou
January 7th 2007, AEA, Chicago
Centre for Longitudinal Studies, Institute of Education,
University of London
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Motivation

Does the employment of mothers of pre-school
children have any adverse effects on children’s
subsequent development?
 Do cognitive and behavioural outcomes differ?
 Does any effect wear off or emerge as children get
older?
 Is behavioural as well as cognitive development
transmitted from one generation to another?
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Literature
•
•
•
•
•
US: some adverse effect of employment ( esp fulltime) when child very young on mid childhood
outcomes ( eg Waldfogel, Brooks Gunn, Ruhm),
UK Gregg et al and HJ+GV, esp on literacy skills
Other UK Negative effect on qualifications in young
adults ( Ermisch and Francesconi, HJ+GV on 1970
cohort)
Sleeper or cohort effect?
Most estimates mixed and modest
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Data : NCDS 2nd generation






Women in the 1958 Birth cohort who had children in
1991 at age 33
One third sampled: assessments on any children 4-17.
N = 1136 mothers, 1730 children
( 53% mothers have 2+ kids in sample)
4 assessments on each child, cognitive and
behavioural at 1991 x-section
Child age at assessment ranges 4-17
Longitudinal data is on mothers, who are all the same
age at assessment
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Multilevel Multivariate Method

Outcomes (i) nested in children (j), nested in families (k):

Yijk = αi + ΣEtjk βti + ΣXjkγ i
+ ΣZk δ i + Σ νij + Σ ijk

where, t indexes the pre-school age of the child when the
mother was employed E
 Xjk other child-specific controls and confounders

Zk mother/ family specific controls and confounders
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Outcome variables


Two cognitive assessments of children on PIAT
 Reading recognition (ability in oral reading)
 Mathematics score
Negative of behaviour problems reported by mother on the BPI
or Rutter A scales
 Absence of Aggression/ anti social behaviour
 Absence of Anxiety/ withdrawal
 Internally standardised by including age and age squared in
regressions -sample has a-typically young mothers
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Employment variables

Mother's Employment History
 First year of child's life



Some employment
Employment missing
% kids
27
17
Child aged 1 to 4


Some employment
Employment missing
57
11
Poor dating and poor info on hours worked implies
binary indicator rather than more detailed measure
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Signs and significance of estimates of main effects model
Maths
Employed when child 0
Employed when child 1-4
Controlling for:
Child's age
Child’s age squared
Mum’s reading score at 7
Mum’s ability at 11
Mum's non-aggression at 16
Mum' non-anxiety at 16
Mum Mid Education
Mum High Education
Girl
Birth order
Any younger sibling
Health problems
Step father
Lone mother
1st birth at 20 or before
Social housing
+
+
+
+
+
+
+
-
***
***
**
***
-
**
**
**
***
***
-
following lives from birth and through the adult years
**
***
*
Reading Non-Ag
Non-Anx
+
**
+
+
+
+
+
+
***
***
***
***
+
+
***
***
*
***
+
+
+
+
-
***
***
***
***
-
***
*
**
+
+
+
+
+
-
-
***
-
***
*
***
***
**
*
***
+
+
+
+
+
-
***
***
*
***
***
**
-
www.cls.ioe.ac.uk
Estimated Effects of Mother's employment on child scores
*
tenths
of standard deviations of scores
2.0
significantly different from zero at 95% level
Job while
Child
under One
Job while
Child aged
1 to 4
*
0.0
-2.0
AGE 0
Maths
Read
~Agg
~Anx
following lives from birth and through the adult years
AGE 14
Maths
Read
~Agg
~Anx
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Comparison with ALSPAC cohort – born 1991-2
Estimated impact of early maternal employment on reading/literacy scores
compared with no job ( background controls, no interactions)
SD*0.1 with 95% conf. limit
2
1
0
-1
-2
NCDS
Any 0 -12
mths
Any 13-59
mths
ALSPAC
FT 0-18
mths
PT 0-18
mths
Any 19-34
mths
Mother's employment during child's age in months, by Study
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Estimates of Interactions: Reading
Interactions: mother’s past employment by educational attainment
Employed when child 0 & Low Education
Employed when child 0 & Mid Education
Employed when child 0 & High Education
Employed when child 1-4 & Low Education
Employed when child 1-4 & Mid Education
Employed when child 1-4 & High Education
Interactions: age of child by Mothers Education
Mid by age of child
High by age of child
Mother’s Education
Mid
High - ‘A’ Levels or more
age
age squared
Other terms not shown
following lives from birth and through the adult years
-1.146**
-0.719
-0.223
0.753
0.471
-0.998
0.017**
0.031***
-0.171
0.605
0.259***
-0.138***
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Reading/literacy coefficients on early employment
by education of mother: NCDS and ALSPAC
NCDS Any job , Child aged under 1
ALSPAC, any full-time job when child under 18mths; Literacy at 7
sd*0.1 with 95% confidence limits
A
ALSPAC
NCDS
5
0
-5
NCDS
Low
Mid
High
ALSPAC
None/cse
O level/voc
A level
Degree
Mother's education
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Estimates of Interactions: 3 other outcomes
Maths
Non-Agg
Non Anx
-0.439
-0.643
0.676
-0.679
2.573**
2.484**
Employed when child 0 by age at assessment
0.007
0.004
-0.001
Employed when child 1-4 by age at assessment
0.014*
-0.034**
-0.030**
Employed when child 0
Employed when child 1-4
Interactions: age of child by mother’s past
employment
Interactions: age of child by mother’s educational
attainment
Mid Education by age of child
0.004
High Education by age of child
0.021*
Other terms not shown
following lives from birth and through the adult years
www.cls.ioe.ac.uk
Conclusion
Some negative association of mother’s employment in first year of life and
reading: as in first generation NCDS and ALSPAC
Estimates generally very small and poorly determined
Only evidence for systematic deterioration by age of child is that initially
favourable impact on behaviour wears off.
Externalized behaviour more systematically related to the other socio-economic
determinants of cognitive development than internalised ( anxiety)
Intergenerational transmission of cognitive skills stronger than that of (one
parent’s) ‘soft skills’
Sleeper or Cohort Effect? Data on daycare and father involvement lacking, but
likely to have improved since the 1980s. Newer evidence should reveal.
following lives from birth and through the adult years
www.cls.ioe.ac.uk
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