[mlyle]

Just to augment/explain what others are saying:

* Liberalizing birth restrictions can't have any effect on the number of workers until ~20 years later, and in practice much later than that.

* Once the population pyramid has begun to invert, you have fewer people of childbearing age. Reversing the policy cannot replace the children who were not born a few years ago to families who are now beyond the point of seriously considering more children.

* In practice, once having fewer children is socially normalized, it's difficult to have a larger family going forward, and...

* Once you have a severely inverted population pyramid, the cost of supporting elders increases and the economic situation of those of working age deteriorates, which tends to further suppress births.

It takes a long time for these trends to reverse.