Hello Jeff,
Yea, I am so pleased that you found the article interesting. I fully understand your point about the possibility of the "risk-free" rate of return being negative. However, because securities can be shorted, the only rate that is truly neutral to both parties is theoretically, zero percent. Of course, the counter argument is that markets determine the clearing price between buyers and sellers. When I wrote this piece almost four years ago I could not imagine a world in which there would be price takers below zero percent interest! Egads! I think this is an example of people's minds taking them into a place divorced from the actual meaning of number and numbers. Philosophically, zero percent literally corresponds to nothingness, or no actions undertaken. But arbitrage thinking allows rates lower than zero percent. Very strange times. In any case, even if zero percent as philosophy does not survive practical reality, the concept of taking the lowest-available rate does survive intact : )
Thanks for taking the time to share your views!
Jason