Кeep all ask and bid orders for all fiat currencies versus BTC in the blockchain. This is possible without changing the protocol. Allow peers to vote for each order, just like they vote to confirm or reject the transaction. Orders which are going to perturb exchange rate against any fiat up or down by more than 0.015% per day would to be suspended or knocked out by peers (no central control involved). This way exchange rate would not change by more than 5% per year. Then let all online exchanges execute orders from same blockchain.
Okay that's an interesting one yvv, thanks - made me think for a while. But I'm already imagining how to game the system because the issue is that someone must decide 2 things externally: What do you peg it to (i will manipulate this) and what percentages do you set (i will game this also). Game case 1: The rate of change between two fiat currencies changes more in one day than whatever limit the system imposes - GAME ON. Then philosophical flaw case 2: If i buy a bag of groceries for .2 BTC one day, how meaningless would a reference to a central fiat be? Lastly, bad-guy abuse case 3: I customize my local Bitcoin client to LIE on the amount of fiat i bought my BTC at. How would other clients know I lied? And how would anyone stop me from buying above or below the system's target rate? I'd only need a modest sized bot-net to start pumping the market rates artificially before i make my sale and let it dump. And silly case 4: face to face cash BTC exchanges - how meaningless does it become then?
So in the end, as will all other Bitcoin "improvement" ideas I've seen to date, the end result is less elegant and beautiful than what is now implemented, and the desired goals are easily circumvented leaving vast holes open for abuse.
No. The current volatility of Bitcoin is due to its infancy and small scale. Hell *I* see the market shift some days directly by my actions when I just sell 10 BTC. On the smaller exchanges, selling 10BTC can swing the value by 5-10 bucks sometimes. But I see this as a growing pain and short term opportunity for the savvy. We traders by shuffling funds between highs and lows are facilitating liquidity and we need *a lot* more of this trading activity to nullify the chance for a quick buck via this very activity. If there were only a few thousand people trading Dollars the same would be the case, but as a market grows, the volume will smooth things out and mature it into something stable over time which people can trust for normal commerce. We are years off still but it's inevitable IMHO because the central banks will keep screwing people and going bust, tax payers will keep paying, and the Bitcoin protocol will just.... chug along. We just need to sit tight while the Bitcoin ecosystem is built out and public awareness grows. A few more banking panics will also help, but in the short term expect a bumpy ride.
For the next years until reaching maturity, BTC will always be low when the press (and public) forgets the horrible state of the global banking system, and skyrocket again when reminded. (I'm talking to you Cyprus.)