It's not the miners that count, rather than economic majority.  It's a
surprising fact, but here's how it works: lets imagine 75% of the
miners decided they'd change the economic rules, in a protocol
incompatible way.  Result: the miners form a new alt-coin with no
users.  Bitcoin difficulty adjusts, and carries on as if nothing
happened.  The hostile miners earn 25 forkcoins which have  a market
price of 0.  They are burning electricity so they either go bankrupt
or the give up and rejoin the network.

There's a lot to game theory that is subtle.  It could do with a FAQ
writing on it really.

Adam

On 28 June 2015 at 23:04, Sean Lynch <seanl@literati.org> wrote:
> By the way, "consensus" is a red herring thrown out by those who never want
> there to be a fork. There can never be consensus for a fork, because
> otherwise it wouldn't be a fork. Claiming there needs to be consensus is
> just a way to try to make it look like any fork is somehow unilateral and
> undemocratic. But to succeed, any fork by definition needs broad support. In
> fact, it's about the most democratic you can get: people put their money and
> their mining power on the fork they want. It's those opposing any fork who
> are the authoritarians. Obviously, when you consider who's making the death
> threats.