4

Why did miners/pools choose the longest chain for continuing it?
Because with this strategy they have the highest expected bitcoin reward.
The expected bitcoin reward is `(new generated bitcoin (b) + transaction fees (t)) * probability (p) the block will not become orphaned`

.

Since today `b + t`

is clearly dominated by `b`

and `b`

is kind of constant, today miners maximize `p`

by mining for the longest blockchain. But what about the days when `b`

gets close to `0`

? Then, right after a completed block, `b`

and `t`

are `0`

. Thus, a clever miner should ignore the latest block, since even with a small `p`

he will end up with a higher expected reward.

But once miners become aware of transaction fees and will not build on the longest chain this could cause serious trouble? Did I forget something or are these assumptions right?

1The assumption that t starts out as 0 is wrong. Not all transactions will be included in every block. – Meni Rosenfeld – 2013-02-14T06:16:55.487