"According to the IMF, the Australian big four banks are the most highly concentrated in the world.Given the increasing concentration of market power in the hands of the big four banks, we would expect to see an increase in the profitability of those banks.(David Richardson, http://www.dissent.com.au/banks-just-too-big/ )"

Critically assess the following propositions:

a)Major four banks have too much market power in the Australian financial sector and the client benefit is falling due to the market power of four larger banks.

b)More competition in the banking industry is good for the Australian financial sector.

provide reference to answer.