This is just published in the Journal of Development Economics, from Chris Bidner and Mukesh Eswaran, and the title is “A Gender-Based Theory of the Origin of the Caste System of India”:
We propose a theory of the origins of India’s caste system by explicitly recognizing the productivity of women in complementing their husbands’ occupation-specific skill. The theory explains the core features of the caste system: its hereditary and hierarchical nature, and its insistence on endogamy (marriage only within castes). Endogamy is embraced by a group to minimize an externality that arises when group members marry outsiders. We demonstrate why the caste system embodies gender asymmetries in punishments for violations of endogamy and tolerates hypergamy (marrying up) more than hypogamy (marrying down). Our model also speaks to other aspects of caste, such as commensality restrictions and arranged/child marriages. We suggest that India’s caste system is so unique because the Brahmins sought to preserve and orally transmit the Hindu scriptures for over a millennium with no script. We show that economic considerations were of utmost importance in the emergence of the caste system.
There are ungated versions of the paper here. Here are earlier MR posts on the Indian caste system. I think I am not enough of a rational choice theorist to believe in any explanation of this sort, still it is sometimes better to try and fail than never to try at all…
The pointer to this paper is from Michael Clemens.