Since Independence, for the first time, India’s demographic profile stands at a telling cusp. The median age of an Indian is around 29. We are the world’s most populous country. The gender balance has improved: NFHS 5 ( National Family Health Survey ) recorded 1,020 women for every 1,000 men, compared with 991 just a few years earlier. Women’s educational attainment has improved sharply, and India has made progress on several measures of gender parity. And yet, beneath these reassuring numbers, a quietly unfolding trend is the total fertility rate — at 2.0, it has fallen below the replacement level of 2.1.

A recent study of women, aged 36 to 49, points to an emerging section of educated, urban and relatively affluent women remaining outside the traditional pathways of marriage and motherhood. Among women who do marry, the family structure is becoming leaner, with fewer children.…