What to do when young adults in the prime refuse to reproduce?

I suggest that the best years to reproduce in the 21st Century is between 27 and 32 for people in the industrialized West.

However in this, our best reproductive adults are apparently failing us. 

Here is one country that is in a mess:

http://www.csmonitor.com/World/Asia-Pacific/2017/0129/Singapore-s-plea-to-its-people-Won-t-you-please-have-more-children

We in Canada are in the same pickle. So solve our problem we are importing people from other nations.

For this the Canadian population has now soared to 36+ million.

Japan is actually in a worse demographic mess than Singapore.