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Socio-economic and spatial determinants of sex differences in undernutrition in India

Judith Hübner, TU MunichStephan Klasen,University of Göttingen

Stefan Lang, University of InnsbruckSFB Workshop, October 12, 2006

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Introduction• Large gender bias in infant and child mortality in

India (39 million „missing females“ 2001);• Pronounced spatial pattern of female

disadvantage in mortality (North-South differential);

• Pronounced spatial pattern of undernutrition (for both sexes) in India (similar North-South divide)

• What‘s the role played by gender bias in undernutrition?

• Socio-economic and spatial determinants of sex-specific undernutrition in India.

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Data and Measurement

• Data: India National Family Health Survey 1998/99 (32000 observations of children below age 3)

• Undernutrition measure: Insufficient height for age (chronic undernutrition), calculated as a Z-score:

• Use measure as continuous variable.

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Girls: Significant EffectsBoys: Signficant Effects

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Economic Theory• Undernutrition depends on economic resources

and knowledge at the household level as well as access to services;

• Differences in treatment by sex related to ‚investment‘ decisions of households as well as bargaining power of parents;

• ‚Investment‘ depends on sex differences in economic opportunities, marriage and old age arrangements;

• Bargaining power depends on sex differences in economic opportunities and social freedoms for males and females.

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Modeling Approach

• Geo-additive semiparamatric model• Fully Bayesian inference (restricted ML a la

Fahrmeir, Kneib, Lang, 2004)• Fixed effects: Diffuse priors, non-linear effects:

P-Splines, interaction age-breastfeeding: low rank kriging

• Sequential estimation: First semiparametric model, then analysis of spatial structure of residuals (problems with simultaneous fitting).

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Categorical Covariates

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Metrical Covariates

Women‘s and Economic Status generated via first principal component !

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Fixed effects (girls)

Competition for resources worsens nutritional status compared to boys (e.g. twin, birth interval, first born, household size effects), strong religion effect (Islam and Sikh bad), effect of being ‚wanted‘

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Fixed Effects (boys)

Boys particularly affected by health hehavior, less by competition (more „vulnerable“?)

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Important Non-Linear Effects

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Important Non-Linear Effects

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Important non-Linear Effects

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Residual Spatial Effect

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Girls: Significant effects Boys: Significant Effects

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„Success“ of Empirical Model

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Conclusions

• Are able to explain much of spatial pattern in undernutrition in India (better for boys than girls); but significant spatial pattern remains;

• Role of competition for resources (girls) versus health behavior and breast-feeding (boys);

• Critical to extend research to sex differentials in mortality.