Your question "If population growth was undesirable, why would people migrate to cities in such large numbers?" unnecessarily conflates 2 separate issues. Issue 1. Is population growth undesirable ? - Yes & No. If initial population is small, then No. Otherwise Yes, simply because physical constraints matter. Nobody wants to live in a crowded chawl - humans need space to flourish, we're not sardines in tin can. Issue 2. Why do people move to cities ? Some move to big cities, some move from big cities to smaller cities, some don't move, some even move to villages etc. Depends on their priorities - whether social ( parents etc. ), economic ( mostly jobs ), weather ( no pollution ), some combination of these. If Indians are moving to cities in vast numbers despite crowded conditions & pollution, it just means they value economic security ie. jobs, better schools so kids get better jobs in their future etc., more than better living conditions elsewhere, which perhaps don't exist in the Indian context ie. their moves aren't entirely out of free will, they're constrained. For unconstrained movements of people, look at Europe, or say the US - people move from the greatest city NYC to upstate NY say Rochester, all the time. Why ? Much better living conditions for minor economic tradeoff. People move from Silicon Valley to Austin, Wall Street to Greenwich, Denver to Boulder, Chicago to Madison. Boston to Providence, to Vermont, even Maine. Larger city to much smaller city. Happens all the time. Sizeable numbers too. Why ? Better quality of life triumphs minor economic gains. Every time. You posit a flawed problem statement & then think it through also :)