The rate of inflation of steem lessens each year. It's around 9% right now.

The SBD (steem backed dollar...which is a different thing than Steem) was designed to stay around 1.00 in price....but as we've seen in the markets over the last many months it's quite possible for it to be traded for more and less. SBD's i think peaked at around 2.00 in june.

The price of Steem will rise with increased capital coming into the platform...stronger demand for it. With enough interest coming in for steem it is not that difficult for the price to climb...as a large percentage of the 'utility' of steem is in locking it up into steem power.