India, June 6 -- First China, and now Vietnam have lifted policies capping the number of children allowed, underscoring the unintended demographic consequences of such interventions. This should serve as a warning to other countries against direct and indirect coercive measures to curb fertility. A rapid fall in birth rates, quite like the case with China before it scrapped its one-child policy, has now forced Vietnam to scrap its two-child limit for families - its total fertility rate (TFR) hit the replacement rate of 2.1 in 2021 and fell to 1.96 in 2023. With societies getting older and living longer, limits on children portend a future demographic - and thereby, economic - problem of not enough young, working hands and rising numbers of those needing care and social security. To be sure, countries without such policies, especially developed ones including South Korea and Japan, have seen TFR decline to alarming levels. But there is no doubt that limiting the number of children through inducements and deterrents exacerbates the problem. What worsens the fallout is that reversing such policies and incentivising childbirth doesn't always work - at least not immediately, as the experience in some countries that have tried to get their young people to have more children and correct declining demographic trends has shown. The associated demographic imbalance too, has been clear for some time - from sex imbalance due to gender preference to sharp divides along rural-urban and educational attainment lines. To that end, countries flirting with child limits should be well reminded that, in the quest to avoid Malthusian horrors of overpopulation and promote a designer society of controlled fertility, the need for demographic balance must not be sacrificed. The law of unintended consequences has been too clearly demonstrated by China and Vietnam to be ignored....