This is absolutely a governmental issue- S Korea and the US are similar in that people are having fewer children in these places because having children is prohibitively expensive. Having children is prohibitively expensive because income inequality is at an all time high - a smaller and smaller portion of people are able to capture more and more of the resources. Income inequality is a direct result of government policy and can be mediated with changes to those policies. It's happened before, and it can happen again.