This is too easy because Steemit needs to be obscure, obtuse and confusing by tradition, but here is a simple answer:
Issue a token worth 1 USD of steem or SP.
Call it a dollar coupon or whatever. You can't call it a dollar because the feds will be all over you in 2 minutes, but there is no law saying you can't have something worth a dollar.
It could be the SBD, but that can of worms is too far gone to even bother to mess with it. I say get rid of that.
Steemers can convert the dollar coupon to SP if they want the voting power or convert it to steem if they want to trade it for bitcoin to trade for local currency.
All the complex algorithms underpinning Steemit are calculated the same except that rewards are posted in do11ar coupons (or whatever you want to call it) instead of SP and SBD.
Make the $1 coupon one way in that you can only get out of it by exchanging it for steem or steem power.