India, June 16 -- India's biggest cities, unlike the country as a whole, are still growing rapidly. Delhi, the national capital, is the biggest example. Numbers from the household enumeration exercise of the ongoing census record a 60% increase, from 3.4 to 5.5 million in Delhi between 2011 and 2026. Delhi's expected population is likely to be around 23 million, up from 17 million in 2011. To be sure, the numbers are not surprising and align with official projections.

Migration, both of the rich and the poor, rather than procreation, has been driving Delhi's demography for decades. For those who live there, the city is bursting at its seams. Infrastructure is stretched. Regulation is farcical. Both air and water in the city turn toxic pe...