People deciding not to have kids has almost nothing to do with the support available, and very much to do with women having alternatives.
In many countries in Europe, there is very generous parental leave, subsidized childcare, tax bonuses, etc. And still the birthrate is dropping. I, for one, find it rather enheartening that when you give women something other to do than obsess over offspring, a good many will say "fuck this noise" and focus on career, personal fulfillment, and so on. (Those who do have kids tend to get so obsessed with them that they don't have the energy to spare for more than one, at most two.)
Meanwhile, who reproduces the most? It is women in poor countries with low education. Usually in such countries the government doesn't provide any support at all, and people can only expect help from their families.
So if a government really wanted to raise the birth rate, the solution is not to offer more benefits, but to completely remove them all, including retirement savings schemes and mandatory childhood education. A nation full of uneducated women will result in more children, but the all-important economy will probably take a nose dive with a lack of skilled workers.
I'm so sick of all this moaning about low birth rates. The world's population is still rising, and the environment is utterly fucked thanks to the "economy". Why don't we use this precious opportunity to stop bemoaning the Ponzi-scheme we have, and start considering a more sustainable model? The "thinkers" we have today are anything but visionary; they can't even imagine an economic system that isn't based on the illusion of perpetual growth.