How responsive are nutrients in India? Some recent evidence

Abstract

The relationship between nutrient intake and income is an issue of huge policy relevance, especially in the developing world. Using large-scale household-level data from India, this paper analyzes how macronutrient and micronutrient intakes respond to changes in income in both rural and urban areas. It also investigates how food consumption patterns change over time. In a first, this paper employs different estimation approaches i.e., parametric, semi-parametric and non-parametric estimation models to obtain more recent and robust nutrient-income elasticity estimates for three macronutrients and four essential micronutrients. The parametric (OLS) calorie-expenditure elasticities were lower than those estimated for protein and fat. Micronutrients also yielded positive and statistically significant elasticities. In terms of the parametric (IV) estimation, elasticities also declined over time and had lower magnitudes than the parametric (OLS) estimates. Relative to protein, fat and micronutrient intakes, caloric intakes are less sensitive to changes in income. According to parametric (OLS and IV) estimation, calcium is the most income-responsive micronutrient, while zinc is the least. The preferred semi-parametric estimation strategy provides full flexibility to income effects while also simultaneously controlling for additional covariates parametrically, assisting in determining the true relationship between nutrient intake and income. Consistent with the parametric estimation, elasticities were positive and statistically significant. The augmented semi-parametric elasticities, which address endogeneity concerns, were lower than the non-augmented ones. The semi-parametric elasticity curves depict that the relationship between demand for nutrients and income is indeed non-linear and non-monotonic. The findings from this research demonstrate that it is critical to evaluate the effect of income across the entire income distribution, and not just at the means. Even when the elasticities are low, they are always more pronounced for the poor, who are the most vulnerable to malnutrition. The study conducts a battery of checks that further lend credence to the robustness of the main findings. Given the current landscape of India’s nutrition economy, the findings of this study would serve to be useful for designing apt future nutritional interventions and public health policies.