The paper argues 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. 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, fertilising and weeding operations, which are typically performed by women. 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.
The study thus aimed at testing the hypothesis 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 labour. 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.
The study used data from multiple sources, namely from the 1991 Soils of India, The National Sample Survey data, data from the Census of India, Weather data from the Indian Meterological Department, data from the 2000-2001 Agricultural Census and Input Survey, 1997-2001 Indian Agricultural Statistics.
The analysis offered an economic explanation for the spatial heterogeneity in the rural 0-to-6 year old sex ratios in India. Deep tillage, only possible in areas with loamy soil texture, reduced female relative to male employment and had a negative influence in the ratio of female to male children. Soil texture explained 62% of the within-state variation in female agricultural labor force participation and 70% of the variation in 0-to-6 year old sex ratios. A 10 percentage point greater fraction of loamy relative to clayey soils was associated with a 5.1 percent lower share of female agricultural laborers and a 2.7 percent lower ratio of female to male children.
The study also found that the relationship between soil texture, relative female labor force participation and the ratio of girls to boys was significantly stronger in the patriarchal North of India than in the more gender equalitarian South. Moreover, the relationship between soil texture, relative female labour force participation and the ratio of female to male children had not significantly changed between 1961 and 2001. The results of this study suggest that although other factors may improve, the absolute survival chances of girls, their relative disadvantage in survival will remain as long as the gender gap in labour market opportunities persists.
A copy of the paper can be downloaded at this link