The greater or lesser ability to cushion the effects of population ageing

In principle: As long as its population is young, and its working-age population is growing faster or as fast as its total population, a country must accumulate external assets; When its population has aged, and as long as the working-age population grows less quickly than the total population, a country must use its external assets to support household income (using income from net external assets and sales of external assets). Looking at the situations of the United States, the United Kingdom, Germany, France, Italy, Spain, the Netherlands, Switzerland and Japan, we seek to identify which of these countries could cushion the effect of ageing on the incomes of domestic economic agents. We can see that the only countries where the growth in external assets is compatible with population ageing (in all these countries, the population remaining young and then ageing) are the Netherlands and Switzerland. The most frequent case is an absence of accumulation of external assets when the population is still young (United States, United Kingdom, France, Italy, Spain). In Germany and Japan, despite the ageing population, the accumulation of external assets is continuing.