Quote from: DannyHamilton on September 03, 2015, 07:25:36 AM

Quote from: adamstgBit on September 03, 2015, 04:58:09 AM

i'm telling you what the "consensus rules" are,
Nodes express their acceptance of a new block by mining on top of it and the longest chain composed of valid transactions is Bitcoin.
this is from the white paper. and it wouldn't make any sense any other way.

Bitcoin has evolved since the whitepaper was written. It gives a good introduction to the overall concepts, but the whitepaper gets many of the details wrong.

I think in this case, you are mistaken. At the moment, the majority of the economic power is in agreement with the hashpower. Perhaps this will always be true, but it doesn't have to be.

Imagine for a moment a case where 53% of the hash power chooses a particular set of consensus rules, and 47% chooses a different set of consensus rules. Imagine that these consensus rules are such that neither side sees any of the other side's blocks as valid. Now imagine that 98% of the users (merchants, consumers, charities, etc) all choose to use the same consensus rules as the 47% of the miners. Which is the "real bitcoin? I think that most people would say that the 47% fork is the "Real" bitcoin since that is what nearly everyone is using as bitcoin. The fact that 53% of the miners have chosen to contribute their hashpower to some other chain doesn't really matter.

Now, there are some market forces in play that make this scenario VERY unlikely. Since most people are using the 47% fork, it will be difficult for the miners on the 53% fork to find anyone that wants to buy the coins they are mining. This will significantly reduce their ability to sell their coins and pay for their operating costs. Therefore, there will be significant financial pressure on them to switch back to mining on the other fork.

This is what is meant when people talk about the "majority of the economic power". There is enough financial pressure on miners that they will tend to follow the desires of the economic power. Therefore, in reality it is the economic power that decides which is the "real" bitcoin, and not the miners.

This state can't really persist, though. The chain that only has 2% of the users behind it will rapidly lose value (assuming people can trade between chains), miners will then stop mining it, and it will be orphaned by the longer chain. So I think you two are saying nearly the same thing.