It is also the aging of the population. The median age increased from 37 to 49. Peak consumer spending is about 48. The people who work declines and drops production of income and people age and drops the demand. The real estate collapse in Japan crushed the wealth of the middle class. This is what will happen soon to China, Europe and the world economy.

There are some people who assume that population decline will make the world better and eventually there would be a turnaround to people wanting to have kids. The people in 80 years would have lived through generation after generation of declining incomes, housing prices and mostly long economic depressions and recessions. If the people today have less hope for the future, why would we expect our descendents to have hope for the future if there we are handing them decades of economic hardship?

Another thing to remember is that national and other debts are increasing and the growing burden falls on fewer and fewer people. The per person debt will skyrocket. This would lead to default on the debt.

This will continue and get over twice as bad for Japan. Japan's median age will hit 53 in 2040 and 54 in 2050.

China will hit median age of 47 in 2040 and 50 in 2050.

China and much of Europe are already heading into the same issues that Japan did.

Property prices in China are down 20% with the Evergrand real estate speculation collapse.