Doctor D,

A closer look at China and Japan refutes you analysis.

China has a large pool of poor but intelligent and hard working rural people from which a steady stream of internal migration flows to the coastal cities which are the centres of growth and modernization at present.  Largely, for this reason, China currently doesn't yet feel the full impact of its aging population and the consequences of its earlier 'one child' policy as breaks on economic growth.  In other words, Chinese growth and pace of modernization is as dependent on migration as are Western Europe's but internal migration currently fills the need.

Japan entered a prolonged period of stagnation and population decrease and aging several decades ago and is projected to fall from an earlier population apex of around 120 million to around 80 million over the next 4 decades.  They have been quite creative in developing robotics to fill some of the economic gaps biut this only slows and doesn't reverse the downturn.