The return on equity (ROE) in the banking sector is well above those of the real sector – at 30 June 2013, the highest ROE was 28.6%. I am not aware of any real sector operator posting nearly 30 % returns in 2013, do you?
Banks earn returns not just on their own initial equity, but also on the deposits which they mobilise from the public, which are far in excess of their own equity.