The money supply graph of bitcoin is misleading. It just shows the ceiling. The available coins is what matters for the economy. And that curve will have a maximum in the near future and go down with time. Bitcoin is deflationary by design, because it does not compensate for money destruction (lost keys) or hoarding (anticipated value appreciation).
PPcoin doesn't have that misconception, because the money supply is CLEARLY unpredictable. However, you could generate ceiling functions for various scenarios and market conditions. Based on my analysis I would be surprised if we hit a 100 million ppcoin celing before 2018.
"Hoarded" coins shouldn't be counted out - the entire market cap is what matter, including saved/invested coins.
There's nothing clear to me in the money supply of PPCOIN - I just don't understand how it works ... that's why I asked the question in the first place.
The algorithm is not complicated. Coins are minted through PoW blocks which come once every 10 minutes. PoS blocks also mint coins, but their contribution is almost epsilon.
The number of coins minted per POW block = constant / (difficulty)^0.25
This means that everytime difficulty increases by a factor of 16, the block reward gets cut in half. If difficulty falls, then the block reward increases again.
The assumption is that due to Moore's law, difficulty increases over time, so that minted coins falls. However, since difficulty is also heavily affected by adoption, it is almost impossible to predict what the final supply will look like. The longer it takes for adoption to occur, the larger the supply will be.
The other unique feature is that all txn fees are destroyed, so that the long-run steady state should have coin creation = coin destruction, rather than coin creation = 0 and coin destruction = 0.
PoS blocks increase the money supply by 1% per year. That is tiny. i.e. It takes 70 years for the money supply to double via this process.