A recent paper by Abhijit Banerjee, Esther Duflo, Maitreesh Ghatak and Jeanne Lafortune studies marriage in Bengal: Marry for What? Caste and Mate Selection in Modern India .
The nature of this marriage market (in which courtship begins with ads and letters) allows the authors to gather data on preferences for mates, by interviewing matrimonial advertisers about their preferences over the letters they receive, and then to follow up to determine eventual marriages.
"First, the parents or relatives of a prospective bride or groom place an ad in the newspaper. Each ad indicates a PO box (provided by the newspaper), and sometimes a phone number, for interested parties to reply. They then get responses over the next few months (by mail or by phone), and elect whether or not to follow up with a particular response. While ads are placed by both sides of the market, "groom wanted" ads represent almost 63 percent of all ads placed.
When both parties are interested, the set of parents meet, then the prospective brides and grooms meet. The process takes time: in our sample, within a year of placing an ad, 44 percent of our sample of ad-placers whom we interviewed, were married or engaged although most had placed only a single ad. Of those who got married, 65 percent met through an ad, the rest met through relatives or, in 20 percent of the cases, on their own (which are referred to as "love marriages")."
They find that preferences for caste are very high (emphasis added):
"These alternative estimations methods lead to very similar qualitative conclusions: education, beauty, light skin, and high incomes are preferred. But the most striking result is that the preference for mating within one's own caste is strong: for example, we find in one specification that parents of a prospective bride would be willing to trade off the difference between no education and a master's degree to avoid marrying outside their caste. For men seeking brides, it is twice the effect of the difference between a self-described "very beautiful" woman and a self-described "decent-looking" one."
But they find that the cost of satisfying these preferences is not large, since supply and demand are well balanced within each caste, so that assortative matching that takes account of caste does not look different than simulated assortative matching on other observables when caste is ignored.
Overall, they conclude that matchings are stable, in the sense of the two-sided matching literature, i.e. they find that search and matching frictions are low enough, or preferences well enough aligned, so that matches simulated by the deferred acceptance algorithm are hard to distinguish from those they observe.
Update: the paper is now an NBER working paper http://papers.nber.org/papers/w14958