I'm not really trying to force any particular behavior here, I'm more trying to keep SBD from becoming (more than it already is) a hot potato. As distressed debt that carries the real possibility of principal losses, a significantly higher interest rate is necessary to make it a viable holding. 15% may well not be high enough, but I'm taking a somewhat gradual approach. If I still see signs that it is being sold for lower and lower prices, I will propose further increases.

As for the mechanism for reducing debt, that comes (and is already coming) from conversions, where SBD holders request to be paid in STEEM, which destroys the SBD, retiring the debt. This happens for several reasons:

1. Those with SBD rewards or payments who want to power up may use the conversion function to request STEEM instead of trading it and then power up the resulting STEEM.
2. Traders may engage in a form of statistical arbitrage where they buy SBD, convert it, and then sell the resulting STEEM. This is profitable if the value of STEEM that is received and liquidated is higher than the cost of SBD (plus a cost of capital covering time and risk).
3. Some whales and other community members have been steadily converting SBD without too much regard for profitability. Of course, no one wants to take huge losses either.

All of these are supported by witnesses including a discount in their price feeds, which gives more slightly more STEEM for each SBD converted, as well as the price of SBD not being too high. Recently the discount factor has been about 9% and prior to recent weakness, price had been in the range of 92-96. Personally I feel that a discount factor of about 12-14% with a price of 95-101 is preferable (while offering the same conversion gross margin), but some witnesses have wanted to be more cautious about the size of the discount.