One thing to keep in mind is that the reported GDP is net of inflation and the average market return is not. So, 2-3 percentage points of the gap is explained by inflation. We're also sitting at or near all-time highs from a valuation standpoint, so some of that 8-12% is explained by increased valuations. To get 8-12% going forward, we would either need to see a GDP boom or valuations have to keep growing.

That said, valuations do seem to go up at a higher rate than GDP over the long run, even with those issues accounted for. I'm guessing the rest of the issue is some combination of productivity growth and the fact that GDP is defined by national borders and companies are not. There is also likely some impact from credit cycles, particularly the fact that interest rates declined from 1980 to 2022.

[–] sugar_in_your_tea@sh.itjust.works 2 points 3 days ago

The mean GDP growth rate is ~3%, while the total US market real growth rate is something like 6-7% (S&P 500 since 1960) over that same period.

So it seems the stock market returns roughly double the GDP growth. That seems kind of odd to me. I know the stock market isn't the economy, but why would stocks grow twice as fast as GDP over the long term? Is it because so many people invest their savings there, pushing up prices? Is this an expected correlation between GDP and stock prices?

GDP is defined by national borders

This is probably it. A lot of companies on US exchanges do a significant amount of business in other countries, so it's possible international markets are pushing returns up here. But it seems global GDP returns are similar. I think I need to go find a book about how GDP and markets are related.