The percentage is decided by shareholders. Dividend rates are currently very conservative because the network is young and shareholders want to make sure that there is no danger of the $1.00 US peg slipping.
Drifting off course for a second, there is a concept of “aggregate demand” that is used in discussions on the forum and on our website in sections like https://nubits.com/about/price-stability that is useful to think about.
Pretend there is worldwide demand (over long periods of time, such as weeks or months) for 100 NBT. Also pretend there are currently 100 NBT in circulation as the active supply. Demand equals supply, and the peg is easily maintained at $1.00 US.
Day-to-day however, the demand might fluctuate slightly. Some days the demand might be 102 NBT, other days the demand might be 98 NBT. This is where Liquidity Provider Custodians are useful. They provide buy-side liquidity to purchase those 2 extra NBT when demand is only 98 NBT, and sell them when demand is at 102 NBT. LPCs in effect cancel out the short-term variance in demand that is not representative of the true aggregate demand, and help maintain the peg tighter at $1.00 US.
What happens if long-term aggregate demand declines from 100 NBT to 99 NBT, and the active supply remains at 100 NBT? This is a problem, because now long-term demand is less than supply. This is where parking rates are useful. They incentivize users to purchase that extra 1 NBT surplus supply, and it is a winning transaction for a user as long as they believe demand will eventually rise to 100 NBT or greater again. There are also two other ideas being discussed on the forum (variable transaction fees, and NBT-for-NSR burning) that will be able to reduce the active supply down to 99 NBT. These price stability mechanisms will work in combination to ensure the peg remains at $1.00 US as long as possible.
My main point is that in a fractional system, full reserves of USD are not needed. Right now the Nu network is holding a ratio of about 90% coverage on NuBits; banks in the US federal system often operate at 10% coverage. As Nu grows and discovers clever ways of implementing variable transaction fees and currency burning, the risk of a peg collapse will be reduced further.
