I'm Italian, my PhD in Germany in pure maths is paid 40% more than friends working in Italy with engineering degrees. If I stay in Germany after finishing my degree I could easily make twice the money I could get in Italy regardless of whether I stay in academia or go to industry. Not a strong incentive to go back in the immediate future!

Italy has medium salaries combined with high taxes. That's not a good combination. Having children is way too expensive.

When the average net salary is around 1400€s per month and 75% of taxpayers are below that how can you afford children?

Anyway, I think that shrinking population is healthy for the planet.

The problem to solve is financial: how do you sustain so many retirees with a relatively low working-age population?

I think there's plenty of solutions, but none of them is capitalism-friendly.