At the end of last year I published this blog post about how HBD seemed to be pulling back from getting a "haircut" - and included an explanation of what the "haircut" is:
https://hive.blog/alive/@hirohurl/hbd-back-from-the-brink-of-a-haircut
So far this year, however, the debt-ratio has kept on rising to new highs and is getting closer and closer to the 30% haircut trigger. The screenshot shows the current situation:

It's worth listening to @starkerz to understand why this is bad:
Given all that, I think the interest rate ought to be lowered to 10% for now.
However, one objection to dropping the interest rate when the price of Hive is low is that it could cause investors to sell and leave Hive altogether instead of selling HBD to buy cheap HIVE, thereby driving the price of HIVE even lower.
Of course, even cheaper HIVE would be a compelling buying opportunity. Also, if the haircut kicks in, HBD investors won't be getting any interest payments at all.
!PIMP
!BBH
!ALIVE