How Marriage Markets Drive India's Vanishing Girls Problem

India’s gender imbalance is neither new nor subtle. Skewed sex ratios continue to favour boys, bringing with them consequences that extend beyond demography: a marriage market squeeze, rising trafficking risks, and deeper social strain.

Exciting new research develops a unified theoretical and empirical framework to explain persistent gender imbalances in India. It focuses on two well-known drivers of sex selection: son preference (the desire for male heirs) and daughter aversion (the economic disadvantage of having daughters in a dowry-based society). The central contribution of this research is to provide micro-foundations for the phenomenon of daughter aversion by examining the structure of the marriage market and demonstrating how marriage institutions, wealth, and fertility decisions interact to produce biased sex ratios.

Missing Girls
The authors begin with a striking baseline: while natural sex ratios should be close to parity, India continues to exhibit an excess of boys, implying millions of "missing girls" despite decades of economic progress. This motivates the need to better understand the underlying economic and social mechanisms driving sex selection.

Their theoretical model integrates son preference and daughter aversion within a unified framework, with an explicit account of the marriage market. In India, marriages are arranged within caste groups, are patrilocal — women move to the husband's household — and involve dowry payments from the bride's family. Dowries serve a dual role here: they act as a transfer, a bequest to the daughter, and as a price that clears the marriage market.

Daughter aversion arises, the model shows, under three conditions: no commitment from the groom's family to transfer resources to the bride after marriage; a weaker bargaining position for the bride within the marital household (receiving less than an equal share of resources); and social norms requiring that all women marry, preventing parents from avoiding marriage-related costs. Under these conditions, dowries become an inefficient mechanism for transferring wealth to daughters, making parents with girls worse off and creating incentives for sex selection.

Wealth Effects
A central prediction of the model is that marriage markets exhibit positive assortative matching on wealth — wealthy families marry within their wealth class — which produces hypergamy, where poorer girls marry wealthier men. Crucially, sex selection increases with relative wealth within a caste: richer households face stronger incentives to prefer sons because daughters require higher dowries to secure comparable matches. Lower in the wealth distribution, sex selection declines because poorer families benefit from marrying daughters “upward” and from a relative scarcity of girls.

Sex selection, dowries, and wealth distributions are jointly determined. Families anticipate future marriage outcomes when making fertility decisions, creating a feedback loop between demographic behaviour and market equilibrium. This general equilibrium perspective distinguishes this work from earlier research treating sex selection in isolation.

The empirical analysis uses data from the South India Community Health Study, a census of nearly 300,000 households and about 80,000 children. The evidence supports the model strongly. First, dowries are universally positive and consistent with the model’s structure. Second, hypergamy increases as one moves down the wealth distribution. And third, sex selection is higher among relatively wealthier households within each caste.

The authors further distinguish between relative wealth — position within the caste distribution — and absolute wealth, finding that relative wealth increases sex selection while absolute wealth reduces it. What matters is not how rich a household is, but where it sits in the marriage market hierarchy.

There is also substantial within-caste variation in sex ratios, ranging from near parity among the poorest households to highly skewed ratios among the richest, suggesting sex selection is a pervasive phenomenon embedded in market structure, not a regional or community-specific problem.

Policy Implications
Finally, the authors conduct counterfactual policy simulations. They find that existing policies—such as cash transfers to parents for having daughters—may have unintended consequences. By altering dowries and marriage market prices, these programs can sometimes worsen sex selection overall. In contrast, policies that transfer resources directly to women after marriage are more effective because they bypass the inefficient dowry system and improve women’s bargaining power.

Sex selection in India cannot be fully understood without considering the marriage market. Daughter aversion is rooted in the economic organisation of marriage, and effective policy must target the underlying institutional mechanisms rather than parental preferences alone.