Wealth index
A household wealth index was constructed for all children/households at 1y, using a principal component analysis which included several variables related to house and land ownership, housing quality, access to services (electricity, gas, water, and sanitation services), and household assets (productive assets, durable goods, animals, and livestock). The first component derived from component scores explained 40% of the variance and was then used to categorize wealth into quintiles where the lowest quintile (Q1) represents the poorest 20% and the highest quintile (Q5) represents the richest 20% of the population [