Pay women a decent wage per child, like a good part of the average wage per child until the child turns 18. That'll be a clear incentive to get children. Everything else is just ineffective tinkering. In a classic rural setting children were a labor force. In a modern urban setting they're a very expensive hobby with lots of unpaid labor. In a quid pro quo world, pay up. Children are not free. If that's not possible then a growing population is not economically viable in the current system. Better luck in the next system.
Some regimes have tried to force the issue, banning all abortions and contraceptives. The end result was a population that was shrinking more slowly and orphanages overflowing because children were dumped as people didn't have enough money to support them.
South Korea, Japan, Germany, and many other countries "grappling" with decreasing birth-rates have to consider paying parents for children. They are a full-time job.
I do believe however that it should be tied to performance. The worse you do in raising your child, the more the state inserts itself into raising the child. All parents should have to take mandatory classes on child-rearing e.g what is good food for a child, importance of vaccines, how much sleep does a child normally need, how to recognize developmental problems (speech impediments, physical problems, ...), and so on. Basically, pressing a phone into the hands of your child and letting them watch youtube all day probably isn't good for them, neither is feeding them burgers and smoking around them.
South Korea, Japan, Germany, and many other countries "grappling" with decreasing birth-rates have to consider paying parents for children. They are a full-time job.
"Kindergeld" has been a thing in Germany since a very long time, and it's per child. Does it pay like a full job? No... but parents do get paid.
All these solutions (tax breaks, etc.) don't appear to fix the more fundamental problem of it is too expensive to have a kid, work / life balance does not allow it and homes are too expensive.
Nobody has mentioned it, but as countries develop the birth rate naturally drops. A decline in population is necessary in a world with limited resources
A slow and steady drop is manageable but when the drop is sharp, it will result with a smaller pool of younger generation having to take care an extremely large pool of aging generation with their taxes. China is suffering the after effect of one child policy and they're panicking.
Your first sentence is correct. But if you look at the historical data, the sharpest drop in chinese fertility rate was several years before they introduced the one-child policy, which also ended several years ago without apparently making any difference. Also, fertility rates in Taiwan, South Korea, Japan are even lower. As these rates are also lower than europe, that maybe related more to housing affordability and density, possibly combined with some common evolution of 'eastern' values.