[ThrustVectoring]

Another way is to estimate the net present value of America's GDP by multiplying it by 20 or so, which implies that it's roughly 1% of American wealth.

Alternatively, percentage of rents at office and industrial zoned land would be a good measure. That'd separate out national vs international activity, at the cost of being significantly more difficult to estimate and calculate. I actually don't know how well rents and imputed rents are tracked at aggregate levels and broken down by company, so this may very well be data that we simply don't have access to.

[jklein11]

Out of curiosity, why ~20?

[quantumhobbit]

P/E ratios are around 20 on average I suppose. Meaning earnings are 5% of the market cap of a stock.

GDP doesn't directly correlate to earnings though.

[ThrustVectoring]

Historically, $20 is the price of something that gives you $1/year. This, like, goes back to the medieval era.

[arjunnarayan]

It's just a rule of thumb as to what long run P/E ratios look like in the equity markets.