In the CES model (which this author prefers) if the next number of doubles of DT were the same as one of the last three DT doubles, the next doubling time would be either would be 1.3, 2.1, or 2.3 weeks. This suggests a remarkably precise estimate of an amazingly fast growth rate.
Let us now consider the simplest endogenous growth model … lowering ˜α just a little, from .25 to .241, reduces the economic doubling time from 16 years to 13 months … Reducing ˜α further to .24 eliminates diminishing returns and steady growth solutions entirely.
Indeed:
See also Economic Growth Given Machine Intelligence: