Elisabetta Aurino Young Lives, University of Oxford Francesco Burchi

Children’s Multidimensional Health and Medium-Run Cognitive Skills in Low- and

Middle-Income Countries

Elisabetta AurinoYoung Lives, University of Oxford

Francesco BurchiGerman Development Institute (DIE)

© German Development Institute / Deutsches Institut für Entwicklungspolitik (DIE) 2

Objectives

To examine the effect of child’s height, the most commonly used indicator of health, on cognitive abilities at preschool and primary school age in Ethiopia, India, Peru and Vietnam.

To investigate whether cognitive abilities are better explained by a “suite of health indicators”.

To analyse whether a composite index of health deprivation in early childhood can synthesise adequately the overall effect of early childhood deprivation in health on children’s later cognitive outcomes

To explore a few possible channels through which child health may affect cognitive skills.


Child health and mid-run educational achievements: direct effects

Child health typically proxied by low height-for-age Associations with:

– School completion (e.g. Moock and Leslie 1986 in Nepal; Clark et al. 1990 in Jamaica; Glewwe and Jacoby 1995 in Ghana; Shariff et al. 2000 in Malaysia; Alderman et al. 2006 in Zimbabwe).

– Cognitive abilities (Hoddinott et al. 2008; Behrman et al. 2008)

Some studies analyzed the relationship between child height/stunting and cognitive outcomes of pre-school children (Sanchez 2009; Outes-Leon et al 2011) or of children at age 8 (Crookston et al. 2010, 2013) using Young Lives data.


Child health and mid-run educational achievements: indirect effects on learning

Child health could have an indirect effect on learning abilities, by increasing educational aspirations. In a recent paper Dercon and Sanchez (2013) find a positive and large effect of height-for-age at the age 7-8 on educational aspirations for children of age 11-12

Health and nutrition may affect long-run cognitive functioning by impacting on short- middle-run health outcomes. A number of studies worldwide conclude that better pre-school nutritional status is associated with significantly greater height (Alderman et al 2006; Victora et al. 2008).


Conceptual framework

We model cognitive outcomes as a function of children’s health, parental investments, children’s ability and other educational inputs.

Child health is viewed as a complex, multi-faceted phenomenon: we move from one single measure (height) to a multidimensional measure.

About 15% of “healthy years of life” among children aged 0-4 in less developed countries are lost due to mortality and morbidity, and half of the burden of disease is due to communicable diseases.

Most of the infectious diseases affecting children in developing countries are unlikely to affect height-for-age

Early childhood malnutrition and disease can affect cognitive development in different ways (Jukes 2005).


Econometric strategy

OLS estimation: not causal impact. Omitted variables bias alleviated by the use of cluster fixed

effects and many relevant controls available in the Y.L. dataset.

Several different models for every dependent variable (2), country (4) and round of survey (2):1. With only height2. With all health indicators separately3. With composite health deprivation index

Robustness check: addition of variables related to child’s concurrent nutrition and schooling, and to her cognitive test scores (round 2) were added to explore possible channels.


Data

Panel data from Young Lives, Peru, Ethiopia, Vietnam and India (Andhra Pradesh).

Younger cohort: 1 y.o. in round 1 (2002), 5 y.o. in round 2 (2006) and 8 y.o. in round 3 (2009).

Sampling: non-random selection of “sentinel sites”, and then random selection of children in these sites.

Attrition in the sample is extraordinarily low thanks to to a particular effort in tracking children when they move (Outes-Leon and Dercon 2008).


Indicators of learning skills

To assess children’s verbal and quantitative ability at preschool age (5 years, round 2), we employ standardised raw scores in the following tests:– Peabody Picture Vocabulary Test (PPVT): test of

vocabulary acquisition.– Cognitive Developmental Assessment (CDA)

test: measures children’s grasp about quantity-related concepts.

Children’s abilities at round 3 are measured through: – PPVT– Mathematics Achievement Test: measures basic

numeracy skills. 29 simple arithmetical problems.


Indicators of early childhood health

2 indicators of nutrition (in z-scores): height-for-age (HAZ), proxy for chronic nutritional status, and weight-for-height (WHZ), proxy for acute nutritional status.

1 indicator of morbidity (binary): whether the child has experienced a life-threatening illness or injury since birth (reported by the main caregiver).

Composite index “Multidimensional Health Poverty Index” (MHPI), a multidimensional score of children’s joint deprivations in the health dimension.

3 dimensional cut-offs, equal weights: ranges from 0 (child is not deprived in any dimension) to 1 (deprived in all 3 dimensions)

...a possible proxy for child multidimensional poverty!

© German Development Institute / Deutsches Institut für Entwicklungspolitik (DIE)

Height-for-age z-scores

Weight-for-height z-scores

Life-threatening illness

MHPI

EthiopiaMean -1.48 -0.73 0.30 0.29

SD -1.83 1.39 0.46 0.27

IndiaMean -1.3 -1.21 0.22 0.24

SD 1.47 1.06 0.42 0.26

PeruMean -1.28 0.6 0.32 0.2

SD 1.27 1.11 0.47 0.23

VietnamMean -1.12 -0.62 0.13 0.13

SD 1.25 0.95 0.34 0.21

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Descriptive statistics of indicators of children’s health in round 1


Control variables

Child’s gender; age (in months); ethnicity (or caste in India); child’s mother tongue; disability status; whether the child is first-born; born in a health facility; vaccinations; preschool attendance;

Caregiver’s sex, age, level of education; HH size; sex, age and education of the head of the

household; mother’s and father’s presence, 3 composite indicators for HH economic status;

Robustness check: (1) child’s contemporaneous nutritional status (round 3), as measured by BMI; (2) child school grade completed (round 3); (3) child cognitive attainments (round 2).


Results (1)


Results (2)

As expected, child HAZ has a positive and significant effect on all cognitive skills, throughout the 4 countries

Only exception is for PPVT scores in round 3 in Vietnam The magnitude of the coefficient varies across countries,

outcomes and child developmental stages WHZ is significantly associated with all the cognitive

outcomes in Andhra Pradesh and with Maths scores in Peru. When significant, the magnitudes of the WHZ coefficients are similar, or slightly smaller, to the ones of the HAZ indicator.

Especially in India, both forms of malnutrition work in concert to hinder children’s cognitive development


Results (3)

The indicator related to early childhood life-threatening disease is not significantly associated to any outcomes in any countries, with the exception of Vietnam in Maths.

MHPI is significant in all the outcomes and rounds considered in Andhra Pradesh and Peru, while it is significant in the case PPVT round 2, CDA and Maths in Vietnam, and only in the case of Maths scores in Ethiopia.

With MHPI the adjusted R2 falls and we lose information about the specific health dimension that has an influence on cognition

The suite of indicators is more informative


Robustness check (1)


Table 7. Results from the extended models, Peru Round 3 (1) (2) (3) (4) (5) (6) (7) (8) VARIABLES PPVT PPVT PPVT PPVT MATHS MATHS MATHS MATHS Height-for-age z-scores

0.037 0.036 0.033 0.026 0.057 0.055 0.043 0.052

(3.789)*** (3.583)*** (3.449)*** (3.490)*** (5.919)*** (5.832)*** (4.232)*** (5.349)*** Weight-for-height z-scores

0.008 0.005 0.005 0.005 0.044 0.037 0.034 0.039

(0.818) (0.605) (0.537) (0.591) (3.423)*** (3.030)*** (2.678)** (2.757)** Illness (z-scores) -0.004 -0.005 -0.004 -0.001 -0.010 -0.010 -0.009 -0.009 (-0.434) (-0.450) (-0.390) (-0.148) (-0.896) (-0.886) (-0.785) (-0.713) Completed Grade 2 0.293 0.631 (7.146)*** (7.492)*** Completed Grade 3 or 4

0.368 1.061

(7.318)*** (11.411)*** Bmi-for-age z-scores 0.009 0.022 (0.836) (1.435) CDA raw score R2 z-scores

0.041 0.106

(4.576)*** (4.474)*** PPVT raw score R2 z-scores

0.198 0.170

(10.046)*** (7.813)*** Constant -3.223 -3.217 -2.761 -2.131 -5.919 -5.901 -2.849 -4.849 (-10.882)*** (-10.709)*** (-6.097)*** (-6.626)*** (-11.809)*** (-11.847)*** (-5.516)*** (-9.466)***

Observations 1,762 1,760 1,752 1,720 1,800 1,798 1,790 1,756 Number of clusters 20 20 20 20 20 20 20 20 R3 core controls YES YES YES YES YES YES YES YES Adj. R-squared 0.265 0.265 0.286 0.374 0.251 0.251 0.322 0.287

Robust t-statistics in parentheses *** p<0.01, ** p<0.05, * p<0.1

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Robustness check (2)


Conclusions (1)

1. Does child height affect cognitive skills? With the exception of PPVT scores in round 3 in

Vietnam, the estimates show a positive, highly significant effect

In India a 40% increase of a standard deviation in HAZ would translate into equalising the performances of rural and urban children in CDA scores, while an increase of a standard deviation in HAZ would be equivalent to closing half of the gender gap in Maths scores in Peru in round 3.


Conclusions (2)

2. Does a suite of indicators help understanding the health effect on learning? Evidence of the relevance of WHZ, proxy for acute

malnutrition, particularly in India, where its coefficient is always significant, and in the case of Maths scores in Peru. However, large heterogeneity.

The morbidity indicator, instead, contributes to explain only Maths scores in Vietnam.

While height remains the key indicator, recognizing the multidimensional nature of health provides additional policy-relevant information, not necessarily at higher costs.


Conclusions (3)

3. Can the whole contribution of children’s health be summarized by a composite health deprivation index? a “suite of indicators” approach provides

substantially more information. 4. What are the possible channels?

A large part of the early childhood health-cognition nexus is mediated by variation in grade attainment, especially in Ethiopia, India and for maths skills in Vietnam. However, other channels may play an additional role.

Peru is an outlier


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Detailed info on Cognitive skills indicators

• Raw scores in the Peabody Picture Vocabulary Test (PPVT): test of age-specific vocabulary acquisition. 204 questions, the child has to indicate which picture matches a word presented orally by the interviewer

• Cognitive Developmental Assessment (CDA) test: measures children’s grasp about quantity-related concepts by asking the child to choose among a series of images that best represent the concept expressed by the examiner. The test consists of 10 questions.

• Mathematics Achievement Test is an indicator of children’s basic numeracy skills which consists of twenty-nine simple arithmetical problems (i.e. 2+3=__, or 7x8=__).

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Descriptive statistics: cognitive skills

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Elisabetta Aurino Young Lives, University of Oxford Francesco Burchi