Examining the Relative Contributions of Son Preference, Fertility Decline and Sex-Selective Abortion in the Sex Ratio Transition

Ridhi Kashyap, University of Oxford and Max Planck Institute for Demographic Research
Francisco Villavicencio, University of Southern Denmark and Max Planck Institute for Demographic Research

The significant decline in fertility since the 1980s across Asia has been accompanied by an unprecedented and anomalous rise in the sex ratios at birth (SRB). Although the micro-level mechanisms – persistent son preference within a context of fertility decline and diffusion of sex-selective abortion (SSA) technology – are known, their specific levels and trends underpinning macro-level SRB trajectories are hard to discern with existing data and approaches. We present an agent-based model (ABM) model that examines each of these. Calibrating our model to Indian data, we find that even as son preference was declining over time SRB distortions emerged due to the steady diffusion of SSA technology, which was practiced at third parity births and higher. Experiments with our model reveal that even relatively low levels of son preference (~30 percent wanting one son) can cause skewed SRB levels if individuals practice SSA at low (second or third) parities.