Falling birth rates is a problem in most wealthy industrialized societies. Being up a 4am to greet my wife who's been up since 1am with a screaming child. I'm not sure exactly what kind of benefits could convince us that he needs siblings :) Just saying, that while I certainly applaud the effort. I don't see any easy ways to fix the issue: kids are hard work, there are many other things you could do with your life.
The most fascinating part of this is that, against income, fertility is a bathtub-shaped curve. The poorest and richest have the most kids, which the middle class drags the whole nation down.
I get the feeling many have this idea that the more educated /career-oriented you are, the more you delay kids or have less of them. But that is not the case, past a certain point. Look up any of your favorite elite celebrities for example and how many kids they have. They might never talk about them, but I’d bet most of who you look up have 3+