Early Nutrition and Cognition in Peru: A Within-Sibling Investigation

An extensive literature documents linkages between early nutritional deficiencies and reduced cognitive ability, educational attainment and, ultimately, lower labor market performance. Few of these studies, however, have shown these correlations to be genuinely causal. We reexamine the nutrition and cognition link, applying instrumental variable methods to a sibling-difference specification for a sample of Peruvian pre-school children. We use household shocks and food price changes as instruments. As such our analysis also quantifies the nutritional and cognitive costs of the 2006-08 global food price crisis. We find that there are significant and negative cognitive effects of early childhood nutritional disinvestments: a decrease in Height-for-Age z-score leads to a reduction in the Peabody Picture Vocabulary Test score of 17-21 percent. The accumulated deficits are sizeable considering that these children are only 3-6 years old and are yet to enroll in formal schooling, with deficits likely to widen in later years.Health, Nutrition, Cognitive Development, Children, Peru

All we want is a healthy baby – well, and one that is the opposite sex to what we have already

We all know families with three boys or three girls. Did they go on to have three children in the hope that the third child would be the opposite sex to the first two? Are they disappointed when they have another child of the same sex? In this paper, using two British cohort studies, we construct a sample of parents that only differ in the sex of the third born child when the first two are the same sex. Conditional on pregnancy, the sex of a child is random so it is an exogenous influence on the SWB of the parents. We show that, contrary to previous studies, having three children of the same sex negatively affects life satisfaction. This effect is entirely driven by mothers who have a third girl and lasts for ten years after birth. We conversely find that having two children of the same sex boosts SWB. We offer an explanation for this pattern of findings and discuss its implications

Essays on risk, nutrition and poverty dynamics

This collection of essays explores questions on risk, poverty dynamics and early child development. The first essay analyses issues of cognitive development in early childhood. An extensive literature documents linkages between nutrition and cognition, but few studies show correlations to be causal. Building on Glewwe et al (2001) and Alderman et al (2006), we re-examine this relationship and find a negative cognitive effect of early nutritional disinvestments among a sample of Peruvian pre-schooling siblings. The second essay examines nutritional catch-up growth among poor Ethiopian children and the role household wealth in this process. We find that nutritional catch-up patterns vary across socioeconomic groups: average catch-up growth in height-for-age is near perfect among children in better-off households. However, for children above 5 years of age, household wealth no longer affects height velocity. Our findings suggest that nutritional remediation is effective early on in life, but that this window of opportunity might already be closed by the age of five. The third essay contributes to the literature on poverty traps and thresholds. In spite of their popularity, little empirical evidence supports their existence. Studies testing poverty traps often are restrictive in their methodology (e.g. Lokshin and Ravallion, 2004) or fail to provide causal estimates (Lybbert et al, 2004). This essay tests and finds evidence of multiple equilibria in income dynamics in rural India using a 30-year long panel. Simulations suggest the presence of two equilibria: a stable high-income equilibrium and a low-level unstable saddle point. To the best of our knowledge, the paper provides first evidence of multiple equilibria in income dynamics

Do you want some cash-back?: assessing the demand for a no-claim rebate life-insurance product

Diseña e implementa un experimento de campo en el Perú rural, con el fin de examinar la sensibilidad de la demanda de los productos de microseguros de vida con la introducción de las devoluciones, que son reembolsos parciales de la prima del seguro cuando no se produce alguna eventualidad en el asegurado. Se encontró que las devoluciones crean mayores niveles de confianza entre el asegurador y el asegurado, lo que promete aumentar la demanda de seguros. Los resultados sugieren que las devoluciones pueden ser productos de innovación atractivos en los países en desarrollo

Catching up from early nutritional deficits? Evidence from rural Ethiopia

We examine the nutritional status of a cohort of poor Ethiopian children and their patterns of catch-up growth in height-for-age between three key development stages: age one, five and eight. We use ordinary least squares (within community) and instrumental variables analysis. During the earliest period, we find that nutritional catch-up patterns vary substantially across socioeconomic groups: average catch-up growth in height-for-age is almost perfect among children in relatively better-off households, while among the poorer children, relative height is more persistent. Between five and eight years of age, however, we find near-perfect persistence and no evidence of heterogeneity in catch-up growth. Our findings suggest that household wealth, and in particular access to services, can lead to substantial catch-up growth early on in life. However, for our sample, the window of opportunity to catch up appears to close as early as the age of five.</p

Siblings, schooling, work and drought

In this paper we explore the effect that a recent drought in Andhra Pradesh, India, has had on the school and work patterns of children aged 11 to 12 years. Previous empirical studies have investigated the effect of shocks on outcomes for children but few have allowed for heterogeneous treatment effects across children. Ignoring such heterogeneity might lead to biases in the estimated impact of the shocks. The aim of this paper is to address this lacuna. Using data from Young Lives, a longitudinal cohort study of children, we estimate the average impact of the drought on participation in schooling. We then expand our empirical model to allow for heterogeneous effects across children of different demographic categories – namely gender and birth order. Our analysis shows that ignoring child heterogeneity would underestimate the severity of the effect of the drought on children’s welfare and human capital accumulation. In particular, we find that the drought significantly reduced the time spent on schooling by most demographic groups. The exception is the group most likely to have been involved in agricultural work when there is no drought; the schooling participation of eldest sons appears to increase because of the drought. Furthermore, we trace the impact of the drought on child labour and cognitive development, while we rule out the possibility that the uncovered heterogeneous patterns might be driven by social norms or cultural biases in favour of eldest sons.© Young Lives 2011. All rights reserved. Reproduction, copy, transmission, or translation of any part of this publication may be made only under the following conditions: • with the prior permission of the publisher; or • with a licence from the Copyright Licensing Agency Ltd., 90 Tottenham Court Road, London W1P 9HE, UK, or from another national licensing agency; or • under the terms set out below. This publication is copyright, but may be reproduced by any method without fee for teaching or non-profit purposes, but not for resale. Formal permission is required for all such uses, but normally will be granted immediately. For copying in any other circumstances, or for re-use in other publications, or for translation or adaptation, prior written permission must be obtained from the publisher and a fee may be payable. Available from: Young Lives Oxford Department of International Development (ODID) University of Oxford Queen Elizabeth House 3 Mansfield Road Oxford OX1 3TB, UK Tel: +44 (0)1865 281751 E-mail: [email protected] Web: www.younglives.org.u

Siblings, schooling, work and drought

In this paper we explore the effect that a recent drought in Andhra Pradesh, India, has had on the school and work patterns of children aged 11 to 12 years. Previous empirical studies have investigated the effect of shocks on outcomes for children but few have allowed for heterogeneous treatment effects across children. Ignoring such heterogeneity might lead to biases in the estimated impact of the shocks. The aim of this paper is to address this lacuna. Using data from Young Lives, a longitudinal cohort study of children, we estimate the average impact of the drought on participation in schooling. We then expand our empirical model to allow for heterogeneous effects across children of different demographic categories – namely gender and birth order. Our analysis shows that ignoring child heterogeneity would underestimate the severity of the effect of the drought on children’s welfare and human capital accumulation. In particular, we find that the drought significantly reduced the time spent on schooling by most demographic groups. The exception is the group most likely to have been involved in agricultural work when there is no drought; the schooling participation of eldest sons appears to increase because of the drought. Furthermore, we trace the impact of the drought on child labour and cognitive development, while we rule out the possibility that the uncovered heterogeneous patterns might be driven by social norms or cultural biases in favour of eldest sons.</p

Survey attrition and attrition bias in Young Lives

Longitudinal studies, such as the Young Lives study of childhood poverty, help us to analyse welfare dynamics in ways that are not possible using time-series or cross-sectional samples. However, analysis based on panel datasets can be heavily compromised by sample attrition. On the one hand, the number of respondents who do not participate in each round of data collection (wave non-response) will inevitably cumulate over time, resulting in falling sample sizes, which will undermine the precision of any research undertaken using such samples. On the other hand, unless it is random, attrition might lead to biased inferences. Analysts often presuppose that attrition is correlated with observable characteristics such as household education, health or economic well-being, resulting in samples that include only a selected group of households. However, even if that is the case, non-random attrition does not necessarily lead to attrition bias. Attrition bias is model-specific and, as previous studies have shown, biases might be absent even if attrition rates are high. We investigate the incidence and potential bias arising from attrition in Young Lives following the completion of the second round of data collection. Young Lives is a study concerned with analysing childhood poverty in four countries, Ethiopia, India, Vietnam and Peru. The study, which measures a range of child, household, and household-member characteristics , is following two cohorts of children in each country over 15 years – a younger cohort of 2,000 children who were born in 2001 to 2002 (i.e. aged 6 to 18 months when first surveyed) and 1,000 older children born in 1994-95 (i.e. aged 7.5 to 8.5 at the start of the survey). Sample attrition is particularly concerning in the context of a longitudinal study such as Young Lives where cohort sample sizes are modest and individuals are tracked over a relatively long period of time. This paper seeks to: • document the rates of attrition of the Young Lives study following completion of the second round of data collection; • investigate the extent to which sample attrition is non-random; • analyse whether non-random attrition in the Young Lives sample might lead to attrition bias

An assessment of the Young Lives sampling approach in Ethiopia

The sampling methodology adopted by Young Lives is known as a sentinel site surveillance system. In Ethiopia, the Young Lives team used multi-stage, purposive and random sampling to select the two cohorts of children. This methodology randomised households within a study site while the sites themselves were chosen on the basis of predetermined criteria, informed by the Young Lives objectives. To ensure the sustainability of the study, and for resurveying purposes, a number of well-defined sites was chosen. The sites were selected with a pro-poor bias and to ensure a balanced representation of the Ethiopian regional diversity as well as rural/urban differences. This paper assesses the sampling methodology by comparing the Young Lives sample with larger, nationally representative samples. In doing this, the Ethiopia team sought to: (i) analyse how the Young Lives children and households compare with other children in Ethiopia in terms of their living standards and other characteristics; (ii) examine whether this may affect inferences between the data; (iii) establish to what extent the Young Lives sample is a relatively poorer or richer subpopulation in Ethiopia; (iv) determine whether different levels of living standards are represented within the dataset. We found that households in the Young Lives sample were slightly wealthier than households in the DHS sample. Further analysis revealed that households in rural areas and in urban areas, except Young Lives households in Addis Ababa, were wealthier. Young Lives households in Addis Ababa were poorer than households in the DHS sample. A similar picture emerged when we use t-tests to compare the means for a range of living standard indicators between the Young Lives and the DHS samples. Young Lives households in rural areas had better access to public services such as drinking water and electricity supply, while households in Addis Ababa had less access to basic services. These findings were supported by the comparison of common variables in Young Lives and the WMS. However, Young Lives households were less likely to own land or a house, and had smaller livestock holdings than WMS households. To assess trends over time we compared the Young Lives sample with the DHS 2005 sample. Some of the differences, which we observed in the comparison of Young Lives with the DHS were reduced which indicates some improvements in living standards between 2000 and 2005. The analyses show that households in the Young Lives sample were slightly better-off and had better access to basic services than the average household in Ethiopia, as measured by the nationally representative DHS and the WMS. However, our detailed analysis reveals that, while Young Lives households are located at sites with better access to services and utilities, they hold less land, less livestock. And are less likely to own their own house than the average Ethiopia household. This evidence is consistent with the sampling methodology applied with the Young Lives samples in Ethiopia. Despite these biases, it is shown that the Ethiopian Young Lives sample covers the diversity of children in the country. Therefore, while not suited for simple monitoring of child outcome indicators, the Young Lives sample will be an appropriate and valuable instrument for analysing causal relations, modelling child welfare, and its longitudinal dynamics in Ethiopia