So the debt ratio cannot go above 30% by design.
He literally demonstrated how that happens, nothing you can do if HIVE price falls.
Fun fact: If we changed the haircut debt ratio to 100%, that would be rather arbitrary as well. HBD price is dictated by supply and demand and if people decide to trust it and use it despite blockchain setting a 150% debt ratio, once again there is nothing anyone can do about it. It will work. People trusted a coin that openly set that variable to infinity.
In fact, the blockchain starts printing less and less HBD when the debt ratio hits 20%.
This a good point that is actually overlooked by most people. Most believe that HBD is worth $1 all the way the the haircut threshold (30% debt ratio atm) and only starts losing value once it goes over but historically that has been proved wrong so it was wise to widen the preparatory stage (it used to be as narrow as 9% to 10% before HF that moved the haircut from 10% to 30%). This way supply starts reacting to upcoming risks at a more reasonable point. That's the side that can be handled. The other can not.