What Soil Can Tell Us About Sex Deficits

Soil can help explain child sex ratios in rural areas of India, argued Eliana Carranza, Technical Advisor at the World Bank’s Gender Innovation Lab, in this week’s WAPPP seminar, “Soil Endowments, Female Labor Force Participation and the Demographic Deficit of Women in India.”

Sex ratios – defined in the world of demography as the ratio of females to males in a population – are typically split with the number of females and males. Variations in ratio are often visible by age group, but the biggest variation in sex ratios is actually seen via geography. For example, a few countries in the Middle East and South Asia show a distinct and persistent deficit of women, including India.

The World Bank study that Carranza presented was recently published in the American Economic Journal and argues that child sex ratios in rural India can be explained by differences in soil texture. Carranza argued that these ratios are affected by women’s employment opportunities in agriculture, which vary across different kinds of soil.

This is because the soil texture in a certain region determines the depth of land preparation required to produce a crop there. Deep tillage, which reduces the need for labor in female-dominated tasks such as transplanting, fertilizing and weeding, is only possible in loamy soil textures. Therefore, districts with larger fractions of loamy soils exhibit lower rates of female participation in agriculture. The lower demand for female labor reduces the economic value of girls to a household, leading to lower ratios of female to male children.

The study sees a significant effect of soil texture on agricultural workers' opportunities, which disproportionately affects women. There is not the same effect on the overall male population, since men have other types of employment opportunities, while there are no real alternatives available for women in these regions.

The study found that an additional 10 percentage points in the share of female agricultural laborers in the rural work force is estimated to increase the relative number of rural 0-to-6 year olds by 44 girls per 1000 boys. This would bring the sex ration from an average ratio of 925 to 969, which is above the natural outcome for children of that age. The deficit of girls could be erased by a less extreme 5.8 percentage point increase in share of female laborers in rural workforce.

Carranza's policy prescription is relatively simple: provide more economic opportunities specifically for women. Previous studies show that increasing income is not enough to close the gender gap, and neither is creating more employment opportunities overall. In regions dominated by non-equalitarian perceptions regarding the role and value of women, women’s employment opportunities have even greater influence on labor force participation, which in turn affects child sex ratios.

Photo Source: The World Bank