1. Evidence from the Millennium Cohort Study
Early Maternal Employment and Children’s Cognitive and Social Development:
Evidence from the Millennium Cohort Study
University of North Carolina (Greensboro)
Denise D. Hawkes
15th July 2008

2. Outline of Presentation
Research questions
Data
Model of early maternal employment
Results of determinants of early maternal employment
Model of child outcomes
Results of child outcomes
More on selection
Conclusion

3. Main Research Question
Interested in the impact of early maternal employment on child cognitive development
HOWEVER: Which mothers are employed?
What are the characteristics of those who return to employment?
Are these different from those who do not return to employment?
Do these differences explain the difference in child outcomes observed?
Therefore this paper will consider firstly the determinants of maternal employment and then taking these determinants into account the impact of early maternal employment on child cognitive and behavioural development

4. The impact of government policy
One of the possible determinants of early maternal employment especially in the early months of life is government policies such as:
Maternity Leave/Paternity Leave
Child care provision
Flexible working agreements/Parent friendly practices

5. UK Policy Context Statuary Maternity Leave Statuary Paternity Leave
First 4 months statutory maternity pay and an additional 3 months unpaid job protected leave for mothers who have completed one year full service.
Statuary Paternity Leave
2 weeks paid leave
Sure Start
government programme aimed at bring together, early education, childcare, health and family support through their children’s centres which are mainly located in disadvantaged areas in England

6. What do this policy context suggest?
In UK those in employment before the birth of their child are likely to return to employment 4-7 months after the birth of their child
There maybe interesting differences with the UK as only England has Sure Start
Also the determinates of being in employment prior to birth are also likely to be important

7. Millennium Cohort Study
The MCS is a nationally-representative sample of 18,818 babies within 18,552 families
The cohort members were born in the UK between September 2000 and January 2002 and were living in selected UK wards at age 9 months
The sample was drawn to over-represent those who live in areas of high child poverty, areas of high concentrations of ethnic minorities and the Celtic countries of the UK
The first sweep was undertaken when the cohort members were 9 months old, the second when they were 3 years old

8. MCS Descriptive Statistics – Month of employment
For Natural Mothers
MCS
0-3 months 6%
4-5 months
24%
6-9 months
19%
Not by 9 months
51%
Observations
18389

9. MCS Descriptive Statistics – Month of employment by education level
For Natural Mothers
No qualifications
Up to A-Levels
Degree plus
0-3 months 6%
15%
12%
4-5 months 8%
23%
33%
6-9 months 7%
11%
19%
Not by 9 months
79%
51%
36%
Observations
1737
7651
4591

10. Determinants of early maternal employment model
where
emp is a dummy for whether the mother has returned to work by the time the cohort child is 9 months
child is a selection of child characteristics‘ for example being the first born child
mother is a selection of mother characteristics’ for example their level of education
familyregion is a selection of family characteristics’ for example if they live in owner occupied accommodation and a set of regional dummies

11. Child Characteristics’
MCS
Child Characteristics’
First Birth
1.157
( )**
Multiple Birth
0.558
( )**
Low Birth Weight
0.809
( )*
Odds ratios as this is a logistic regression

12. Mother Characteristics’
Most likely to enter employment by 9 months if:
MCS
between years old at the time of birth
hold qualifications
black ethnic group, not Pakistani or Bangladeshi
AND if employed one year prior to birth of the cohort child

13. Family Characteristics’
MCS
Partnership status: reference married
Single
0.514
( )**
Cohabiting
1.028
( )
Number of other children in the household
0.924
( )*
Other adults excluding parents in household
1.405
( )**
Owner occupied housing
1.630
( )**

14. Region
MCS
London mothers are the least likely to enter employment by nine months
Mothers in the West Midlands and Yorkshire & Humberside are the most likely to enter employment by nine months

15. Early employment and developmental measures at 9 months for MCS
Those who have return to part time or full time employment relative to those who have not worked in the first 9 months of their child’s life report significantly:
more likely their children sleep through the night
more likely their children can sit up
more likely to be able to pass things from hand to hand
less likely to nod

16. Child outcomes & maternal employment
where
childout is the standardised BAS, Bracken or SDQ score at 3 years old
emp is a two dummies for whether the mother has returned to work full time/part time by the time the cohort child is 9 months
child is a selection of child characteristics‘ for example being the first born child
mother is a selection of mother characteristics’ for example their level of education
familyregion is a selection of family characteristics’ for example if they live in owner occupied accommodation and a set of regional dummies

17. BAS Just considering employment
Controlling for all selection variables
Reference: no employment by 9 months
0-3 months
0.16
(0.03)***
-0.03
(0.03)
4-6 months
0.27
-0.02
7-9 months
0.30
-0.01
Observations
11505
Coefficents and standard errors as regressions now, in all regressions we have developmental controls for age at test and gender

18. BAS continued
Just working variables working returning to employment in the first nine months of life is significantly positive
Moderated by the inclusion of child characteristics, although they remain significantly positive
largest and most significant covariates are first born, breastfeed and birth weight
Including mother’s characteristics, become insignificant
biggest and most important effect from maternal education, more education higher scores for children
Including family and area characteristics, all remain insignificant

19. BAS continued part 2 Heckman selection model Subgroups:
no education, just working variables significantly positive for returning after 4 months, with all variables all insignificant
basic education, just working variables all significantly positive, with all variables all insignificant
higher education, just working variables only significantly positive between 7 and 9 months, with all variables all insignificant

20. Bracken Just considering employment
Controlling for all selection variables
Reference: no employment by 9 months
0-3 months
0.13
(0.02)***
-0.05
(0.03)
4-6 months
0.26
(0.03)***
-0.06
(0.03)**
7-9 months
0.34
(0.04)***
-0.03
Observations
10980
Coefficents and standard errors as regressions now

21. SDQ Just considering employment
Controlling for all selection variables
Reference: no employment by 9 months
0-3 months
-0.12
(0.03)***
0.04
(0.03)
4-6 months
-0.23
(0.02)***
(0.02)
7-9 months
-0.25
0.06
Observations
12050
Coefficents and standard errors as regressions now

22. Subgroup selection paths
Employment positively linked:
no educational qualifications
to not first born, not being Bangladeshi, being a home owner, having a partner and prior employment
GCSE and A-Levels
not being a multiple birth, not being Bangladeshi, being black, being a home owner, having an employed partner, not being a student and prior employment
University
not being a multiple birth, being a home owner, having a partner, not having an employed partner and prior employment

23. Conclusion Selection into the labour market after birth
Impact of selection when explaining the relationship between child outcomes and early maternal employment
Other things to consider
Link to other two papers

24.
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