Economic freedom, and getting rid of pervasive and extreme rent-seeking (especially at the local level) which raises the cost of caring for kids, and for the kids themselves to start a new household when they grow up. You can see this in places as different politically as the Scandinavian countries (e.g. Denmark), and the U.S. "Red" states. It just works, it's simply anathema in every way to all sorts of out-of-touch elites.