Gavin Andresen - 2012-04-12 16:22:55

A Bitcoin in which miners can and do vote on how much inflation they'd like to award themselves is not a Bitcoin I'd feel like participating in. But it's the logical outcome of assuming miners are a perfectly informed conspiracy of entirely selfish actors.
The Bitcoin ecosystem consists of more that just miners, and even if miners decided to try to form a cabal to increase inflation merchants, users, and exchanges could all veto their block-chain by simply refusing to recognize it.

I think the policy of which transactions to keep in the memory pool is fundamentally different, because miners can do whatever they like and there's not a whole lot merchants/users/exchanges or other miners can do about it. There's no way to enforce a "first broadcast version of a transaction must be mined" rule, if there was then we wouldn't need the block chain at all.

As for re-writing the blockchain if an after-the-fact, large-fee double-spend is broadcast:  I think that's covered by this case:
Quote
Should a miner put Transaction 1 into the block they're mining and take the smaller fee now, or not include it, hoping that nobody else mines Transaction 1 in the next 3 days so maybe they can mine Transaction 2 and get the bigger fee?

I'm not an expert in game theory, but I believe the winning strategy in the above situation, assuming everybody knows about both transactions, is to mine Transaction 1 right away (any economists reading who know a lot more about game theory than I do?).
Or, in other words, you'd need to be pretty sure that you've got a majority of miners who will cooperate with you to rewrite the block chain. The longer the chain, the harder that will be (because it becomes increasingly likely that one of your co-conspirators mined one of the blocks you want to overwrite).