Earlier quoted context omitted.
Extended maternity/paternity leave (especially in Sweden), child benefits (especially Poland), tax exemptions (e.g Hungarian income tax), subsidised or free childcare and more.
Parental leave in Sweden is 80% of your salary and maxes out at 2500 a month for both partners... In Germany it maxes out at 1800. These aren't incentives since you'd be LOSING money by taking parental leave... > child benefits 120-180 EUR a month per child doesn't even cover half the costs of a child.
Historically that was the default when people had very positive fertility. In Israel & the US where fertility is higher there's even less generous setups than Sweden & Germany.
I suspect if you give people enough money they'll probably start having kids, but it's a very high number. Hungary is currently spending 5% of its GDP on fertility policies with little success [1]. Last year Poland's increase in its child benefit program alone cost 0.7-0.8% of GDP [2].
[1] https://www.theguardian.com/world/2020/mar/04/baby-bonuses-f... [2] https://www.reuters.com/world/europe/poland-approves-child-b...