He uses population growth as an example, but the big point is anything that grows geometrically has a doubling rate, and when you're at 50% consumption your only 1 doubling away from catastrophe. Or if you want to talk about summations, If you want to double the availability of something (say houses) you have to repeat the entire time series of production thus far (not counting removals, like demolitions)
Same with the stock market. A stock is basically priced based on it expected future income flows compared to other investment options like bonds. Most things being equal, you need to build an entire whole new business of equal size if you want to double your share value (without dilution i might add).
This task of doing the whole sum again sounds (doubling) much more difficult than "oh just grow at 6% per year for 7 yrs" (rule of 42).
Same with the stock market. A stock is basically priced based on it expected future income flows compared to other investment options like bonds. Most things being equal, you need to build an entire whole new business of equal size if you want to double your share value (without dilution i might add).
This task of doing the whole sum again sounds (doubling) much more difficult than "oh just grow at 6% per year for 7 yrs" (rule of 42).