This model relies on the idea that use of MicroCash will increase extremely quickly at first to match current economic value of the world, and then at a relatively slower pace later on once everyone is using it - as it will then be limited by annual economic growth. So it works like such, by X years everyone on Earth will be using MicroCash. So expanding from a start of some hundreds/thousands of users to over 8 billion at time X requires a lot of known growth of currency to meet that demand. Then to move forward from this point (X) we will use a value Y as percentage to increase supply per year. Current world economic growth is around 1-5% depending upon who you ask which requires some percentage increase in MicroCash supply to occur to meet such demand, so that is Y. Just some random numbers that could be tweaked follow. From 0 to X years supply will increase at 1000% per year. From then on Y% will be 3% The advantages to this model is that it requires no metrics and the increase in supply can easily be budgeted for by everyone participating. Disadvantages.... it will , in the very least, have large periods of time where the value is highly fluctuating, especially the 0 to X starting period.