I believe that the mining economy is an example of
perfect competition and as such, it is not possible to make an economic profit in the long run.
It is not possible to make ECONOMIC profits in perfect competition. This is significantly different that accounting profits.
D&T I believe you may be wrong. Mining is a potentially perfectly competitive marketplace. Electricity is just an input, those with lower input prices will squeeze out those with higher input prices. Solid plans will make some of the higher input guys harder to kill off than some of the lower input guys, but branding and other items will never effect the distribution.
I do not think it is perfectly competitive right now because of the high risk, and limited market for bitcoins.