In a market where 0% interest on debt still demands a premium, it is safe to say the market is willing to extend more credit than the debt the community is willing to take on. If this happens a SBD will be valued at more than $1.00 and there is little the community can do without charging negative interest rates.

This has come and gone in last weeks. With price feed premiums, more SBD's were created and finally the peg is maintained. (by the way charging negative interest rates is not supported in current protocol)