This point along puts a huge cost on having children, even for people below or just around the poverty line. When sex was the only recreation option available with no known birth control methods, lots of kids was the norm. That has changed now, though. People at all levels of society know that raising a child with an semblance of upward mobility is expensive, and logarithmically so - the good private schools are 10X more expensive than the regular ones, with the international schools going to 100X.
Breaking the norms is difficult, but it looks like the country is already tending towards a voluntary one child policy, at least for any parents that hope their children will live better than they did.