What *is* the economy? It’s people earning and spending money by providing each other with things they want/need. So, if the population is growing, and people’s standard of living is increasing, then you should expect the amount of money spent and earned to also increase.
Now unfortunately, growth doesn’t exactly reflect these underlying goals we have as individuals, because the measures we use to quantify growth are derivative measures, not the measures themselves. You could argue that everyone’s standard of living would go up if we can cut the 40 hour work-week to a 30 hour work week, without a significant impact to productivity. After all, everyone would have an extra two hours per workday to relax, spend time with friends and family, and enjoy life.
The reason you hear about economic growth is that politicians want to take credit for it, in spite of the fact that they have little to no actual control over it.
In the specific case of Japan, you’re right, slowing growth or even recession is not necessarily all that terrible, provided that Japan’s pension system is funded properly.
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