Using analysis of cohort studies to inform social-mobility policy
Submitting InstitutionUniversity of Essex
Unit of AssessmentEconomics and Econometrics
Summary Impact TypeSocietal
Research Subject Area(s)
Medical and Health Sciences: Public Health and Health Services
Summary of the impact
Essex research, conducted between 2009 and 2012, has used cohort studies
to investigate the sources of intergenerational social mobility in the UK.
The results show that two variables have highly significant effects on
children's social mobility patterns: the educational level of parents and
the prevalence of maternal breastfeeding. The cohort analysis conducted by
Professor John Ermisch and Dr Emilia Del Bono shows that there are strong
intergenerational correlations in educational attainment across different
cohorts of UK individuals. The findings have informed UK Government policy
and influenced the work of a major US charitable foundation. Analysis
conducted by a team of researchers led by Del Bono has demonstrated the
cognitive and socio-emotional benefits of maternal breastfeeding, and
shown that its uptake can be used to foster social mobility. These
findings have been vital to UNICEF UK's Baby Friendly Initiative and have
provided evidence to demonstrate its efficacy and to justify its
Researchers at Essex have analysed all available UK cohort data to
explore the sources of intergenerational social mobility. The research
team has found that parental educational attainment and maternal
breastfeeding are key determinants of cognitive achievement in children,
which in turn have powerful effects in determining social mobility in
In 2009 Ermisch and Del Bono undertook research on inequality in
Achievements During Adolescence as part of a cross-national study of the
intergenerational transmission of advantage — the findings of which were
published in a volume co-edited by Ermisch, From parents to children
(2012). This cross-national study was carried out under the auspices of
the Russell Sage Foundation and co-directed by Ermisch, with funding for
the UK component coming from the Sutton Trust. A life-cycle approach was
adopted to understand where in the life-course divergences in outcomes
between high and low socio-economic status children occur, how they evolve
and how those differences may be related to policies, processes and
institutions operating in various countries. Ermisch and Del Bono's
research showed that in England the gap between adolescents with
higher-educated parents and those with lower-educated parents is clearly
evident by age 11, increases between ages 11 to 14, and remains stable
thereafter. They argue that the change in the socio-economic gap was most
likely due to higher-educated parents sending their children to better
secondary schools, as both observed and unobserved secondary-school
characteristics account for most of the increase.
An associated policy report produced by Ermisch and Del Bono for the
Sutton Trust provided more detailed analysis for the UK: (i) over time
(comparing the BCS70 and NCDS cohorts); (ii) over the life-course of an
individual (using LSYPE); and (iii) in an international perspective (using
TIMMS 2003 and 2007). This report, Educational Mobility in England,
focused on the link between the education level of parents and the
educational outcomes of teenagers. This report found, inter alia,
no change in education mobility for the least educated households, but
noted that the advantage of having degree-educated parents had diminished
compared to previous generations.
Del Bono's research on social mobility also included leading a research
team that was conducting new studies on the effects of breastfeeding on
early childhood outcomes. This research, conducted between 2009 and 2012,
needed to explicitly consider the influence of the educational level of
parents since in the UK, as in other developed countries, rates of
breastfeeding are higher among more educated mothers. The main objective
of this research was to investigate whether breastfeeding can have effects
on health, socio-emotional and cognitive outcomes early in life that are
independent of maternal characteristics. In that case, policies aimed at
promoting breastfeeding among more disadvantaged families can foster
The studies analysed the relationship between breastfeeding and: (i)
various child health measures; (ii) indicators of child cognitive
development, including assessments of children's early literacy and
numeracy skills; and (iii) aspects of children's social and emotional
development. Some of the studies additionally provided an evaluation of
policies to support breastfeeding at the hospital level, such as those
implemented by the UNICEF Baby Friendly Initiative in the UK, or those
supported by employers, such as the availability of breastfeeding
facilities at the workplace.
The research found evidence that breastfeeding affects children's health
and cognitive outcomes, and some aspects of social and emotional
development. The findings also showed how hospital-based policy
interventions in support of breastfeeding are an effective tool to
increase breastfeeding rates among less educated mothers, while the
availability of breastfeeding facilities at work facilitates women's
return to employment but only among more educated employees. These results
highlight the way in which existing policies in support of breastfeeding
have different effects on different groups of the population, and while in
some cases may enhance social mobility, in other cases may actually reduce
Research conducted at Essex in 2012, and published in Archives of
Disease of Childhood in 2013, attempted to identify the particular
mechanisms that lead to the association between breastfeeding and
intergenerational social mobility. This research analysed data from the
British Cohort Studies of 1958 and 1970 and found that breastfed
individuals were more likely to be upwardly mobile and less likely to be
downwardly mobile, with similar effects identified in each cohort.
Mediation models identified a key mechanism to be that breastfeeding
advances neurological development, resulting in improved cognitive
performance, which in turn supports upward social mobility and protects
against downward mobility.
The research team included: Professor John Ermisch (left Essex October
2011), Dr Emilia Del Bono (Reader), Dr Birgitta Rabe (Senior Research
Fellow), Dr Maria Iacovou (Senior Research Fellow), Professor Amanda
Sacker (left Essex December 2012), and Professor Yvonne Kelly (at Essex
January 2011 — December 2012).
References to the research
Heikkila, K., A. Sacker, Y. Kelly, M. Renfrew and M. Quigley (2011)
Breastfeeding and child behaviour in the Millennium Cohort Study. Archives
of Disease in Childhood. DOI: 10.1136/adc.2010.201970
Ermisch, J. F. and E. Del Bono (2012) Inequality in achievements during
adolescence. In J. F. Ermisch, M. Jäntti and T. Smeeding (eds.) From
parents to children: The intergenerational transmission of advantage.
New York: Russell Sage Foundation. ISBN 978-0-87154-045-4
Sacker, A., Y. Kelly, M. Iacovou, N. Cable and M. Bartley (2013) Breast
feeding and intergenerational social mobility: what are the mechanisms?
Archives of Disease in Childhood 98 (9): 666-671. DOI:
Del Bono, E. (PI); M. Iacovou, B. Rabe and A. Sevilla-Sanz (Co-Is) The
Effects of Breastfeeding on Children, Mothers and Employers. ESRC
(grant RES-062-23-1693), 01.06.09 to 30.11.11, £192,760.
Ermisch, J. F. (PI) Inequality in Achievements during Adolescence.
Sutton Trust, 01.07.09 to 15.10.10, £39,630.
Details of the impact
The research has informed social-mobility policy in two main ways.
Firstly, through informing strategy, including influencing the policy of
government and third-sector organisations. Secondly, through influencing
the development of practical measures to support breastfeeding — a key way
of fostering social mobility.
Informing social mobility strategy
The work conducted as part of the project on cross-national study of the
intergenerational transmission of advantage has played an important role
in informing the UK policy debate. The first major impact of the study
stemmed from Del Bono and Ermisch's Educational Mobility in England
policy report for the Sutton Trust. The Sutton Trust has stated that "the
research was a centrepiece for an international summit on social mobility
attended by the leaders of the three main political parties. The policy
influence from this was manifested in the Coalition's 2011 Social Mobility
Strategy, which set out a number of key policies attempting to improve
social mobility" [corroborating source 1]. The Educational Mobility
report was referred to in the Sutton Trust's submission (October 2011) to
the House of Commons Education Select Committee inquiry into social
mobility [corroborating source 2]. In addition, the research on inequality
in adolescence, as well as other international evidence on the interaction
between educational institutions and social mobility, was presented at a
workshop held at the British Academy in May 2011 to an audience of
policymakers and journalists .
The Russell Sage Foundation, an American charitable organisation, has
outlined two specific impacts arising from Ermisch and Del Bono's (2012)
chapter on inequality in adolescent achievement. Firstly, the findings of
this work were central to the Foundation's engagement with policymakers
and non-academic audiences. A non-technical summary of the From Parents to
Children project, which highlighted the work of Ermisch and Del Bono, was
devised for the purpose of engaging with such audiences  . Secondly,
the Foundation has confirmed that Ermisch and Del Bono's findings on
income gradients have led to investment in "several grants looking at
exactly these issues to build upon and extend the findings from the
Ermisch and Del Bono work". Further to this, the Foundation now has four
visiting scholars working on these issues and is looking to fund further
projects on developmental patterns .
Influencing practical measures to support breastfeeding
Essex devised a programme of dissemination for the findings of the work
on social mobility and breastfeeding, which has led to various impacts. In
October 2011, Essex organised a policy workshop, `Early Intervention and
Social Mobility: Are pro-breastfeeding policies worth it?' at the British
Academy in London to discuss some preliminary results from the research.
The workshop was chaired by Dr Miriam Stoppard, a well-known author of
books on child development. It featured a panel of healthcare experts and
representatives of third-sector organisations, including Janet Fyle
(Policy Advisor for the Royal College of Midwives), Alison Baum (CEO of
Best Beginnings), Belinda Phipps (CEO of the National Childcare Trust),
and an MP who is both a member of the Health Select Committee and chair of
the All Party Group on Maternity Services .
As an immediate consequence of this workshop, the MP addressed the
under-secretary of State for Public Health in a parliamentary debate on 21st
November 2011 to ask about the provisions set in place by the current
Government to support breastfeeding in the long-term  . The MP, now
a Minister in the Department of Health, has confirmed that various policy
decisions have been informed by the research, including the Government's
support for the Healthy Child Programme, the inclusion of breastfeeding in
the Public Health Outcomes Framework, supporting breastfeeding through
increasing the number of health visitors, providing information about
breastfeeding through the NHS Information Services, and promoting National
Breastfeeding Awareness Week .
Essex research on breastfeeding and social mobility has been vital to the
work of UNICEF UK's Baby Friendly Initiative, which works with public
services to promote and support breastfeeding. The Director of the
programme writes that "ISER's research has been valuable in giving strong
evidence for the efficacy of the Baby Friendly Initiative — particularly
in areas of lower socio-economic status, where breastfeeding is less
common" . The necessity of providing such evidence is that "it is
important that we can show that the programme has a measurable impact on
practice and breastfeeding rates in order that the investment in staff
time and resources is justifiable — particularly during a time when
budgets are being cut" . The Director also states that the research has
been providing vital evidence on why breastfeeding is important,
especially in providing an effective methodology to demonstrate the
association between breastfeeding and IQ . Further to this, Iacovou and
Sevilla-Sanz's 2010 working paper is cited multiple times in a 2012 report
by UNICEF UK on the benefits to health services that breastfeeding
Most recently, the 2013 paper on breastfeeding and intergenerational
social mobility from Archives in Diseases of Childhood has
received extensive media coverage, including articles in the Independent
and Daily Mail. It has also been the subject of a feature on the NHS
Choices website .
Sources to corroborate the impact
All documents are available from HEI on request.
 Director of Development and Policy, Sutton Trust.
 Sutton Trust note for the House of Commons Education Select Committee
session on the Government's new school admissions code (12 October 2011).
 Documentation regarding workshop at British Academy.
 Pew Charitable Trusts' summary of From Parents to Children.
 Senior Program Officer, Russell Sage Foundation.
 Summary of event outcomes, which documents the event.
 Hansard: 21 Nov 2011: Column 209W.
 Minister in the Department of Health.
 Programme Director, UNICEF UK Baby Friendly Initiative.
 Renfrew, M. J. et al. (2012) Preventing disease and saving
resources: The potential contribution of increasing breastfeeding rates
in the UK. UNICEF UK. See pp. 35, 63-65, 70.
 Media coverage of 2013 paper in Archives in Diseases of