The world’s limited natural resources.
Decrease and increase in population.
Economic growth or economic stability (if not growth).
I am wondering about the complex interactions among these factors.
Population cannot increase beyond the bearing capacity of natural resources–food, minerals and all.
Decrease in population can bea problem for a nation’s economy. For example, Japan’s rate of annual population decrease is 300,000 in the last few years. This means that for Japan to remain economically stable, at least where it is (if not grow), every individual of its numerically reduced work force should be more productive, which in the long run is impossible. This is a problem if economic stagnance or reverting to a point of growth in the past is a problem.
If a country of a small population needs an immigrant work force if it should build a more robust economy than its population can make.
In any case, the limitedness of natural resources should be the common denominator of all economic growth theories practices.