The deficit of women relative to men in some societies has emerged as the most extreme indicator of gender-based discrimination (Sen 1990). Studies concerned with the demographic gender imbalance have provided evidence on significant effects of economic factors (Rosenzweig and Schultz 1982, Rao 1993, Larsen et al. 1998, Rose 1999, Qian 2008) and of cultural disparities in the perception of women’s worth (Das Gupta et al. 2003). However, great geographical differences in population sex ratios remain and are more difficult to explain (Basu 1982, Das Gupta et al. 2003).
This study examines the remarkable geographical heterogeneity in infant sex ratios in India. In India, a country characterized by a severe female population deficit, sex ratios are not male-biased everywhere. They differ substantially across districts, even within the same state and cultural region (Dyson and Moore 1983, Agnihotri 1996). Average district sex ratios for the 0-to-6 year old population are more biased in the North than in the South, and range from a minimum of 766 to a maximum of 1035 females per 1000 males.
I show that in India, where 72 percent of the population is rural, there is a significant and important association between the geographical variation in exogenous soil texture and rural infant sex ratios. I argue that the association can be explained by differences in the economic contributions of women relative to men in agricultural production. In agriculture, the depth of land and seedbed preparation are exogenously determined by the soil texture. Deep tillage of land reduces the need for transplanting, fertilizing and weeding operations, which are typically performed by women (Basant 1987). In areas where deep tillage is required, the lower demand for female relative to male labor is expected to have a negative impact on the perceived relative value of girls to a household (Boserup 1970, Bardhan 1974 1988, Miller 1982, Rosenzweig and Schultz 1982, Bossen 1989, Qian 2008, Alesina, Giuliano and Nunn 2010).
Soil texture is a physical property of the soil that is exogenously defined by geological and meteorological factors and that is not easily modified by land management practices. The soil texture is not a chemical or biological attribute and, by itself, does not determine the quality of soil or the type of crop that can be grown. Instead, the soil texture determines the workability and tillage requirements of the soil. Deep tillage can only be done in light soils of loamy texture but not in heavy soils of clayey texture (Muller and Schindler 1999).
I built on the exogenous variation in soil texture to explain the variation in rural infant sex ratios in India. The identification assumption is that, conditional on weather, soil chemical and biological characteristics and state fixed effects, the relationship between soil texture and rural 0-to-6 year old sex ratios across districts can only be explained by the impact of deep tillage of land on the relative demand for female labor. Because smaller relative female labor contributions in loamy areas make girls relatively more costly, the ratio of girls to boys will be negatively related to the difference between the fractions of loamy and clayey soils.
Identification is obtained from the variation in soil distribution across districts within a same state. The district is the unit of analysis where the impact of deep tillage of land can be isolated from other channels. In India, labor markets are geographically small and migration is limited and occurs mostly within district boundaries. Other geographical differences in income, agricultural yield or cropping patterns, as well as in culture, policy, social and economic variables, are not driven by soil texture and are insignificant across districts within a same state. Therefore, differences in the relative female labor force participation and the infant ratio of girls to boys across districts within a same state could not be explained by those alternative mechanisms.
Consistently, I find that the districts with larger fractions of loamy relative to clayey soils exhibit a lower ratio of female to male children. I also find significantly lower female participation in agriculture and higher stocks of deep plows and draft animals per hectare of land in loamier districts. In contrast, I find no evidence of differences by soil texture in crop yields, crop mix or income once other determinants are properly identified.
World Bank.Author: Carranza, Eliana;Document Date: 2012/02/01. Document Type: Policy Research Working Paper.Report Number: WPS5974