There are several different token types that can be issued on the Radix network.
One of the most hotly anticipated is the Radix low volatility coin, which, when launched will have a starting value set to 1 USD/token. The coin value will be 'relatively' stable, not pegged (ie. it is NOT fixed at $1 forever).
Over the longer term, the price will increase in a controlled manner if there is a sustained imbalance between the supply side and the demand side. The higher the sustained imbalance to the demand side, the higher the price and the more tokens will be in circulation. The price discovery process will allow it to float up/down, but the economics will attempt to smooth out the peaks and troughs to reduce volatility.
This is still an experimental coin type and the full details will be released in a coming Economics White Paper.