Here is a nice post by Simon Johnson on what bank capital is and what it is not. Johnson is an advocate of higher capital requirements for banks. In my new book Banking in Crisis, bank capital plays a very important role in contributing to pre-1940 British banking stability and its absence played a major role in the 2008 financial crisis.
According to Robert Shiller , speaking at Davos, Bitcoin is a perfect example of a bubble - story here . Shiller sees Bitcoin as a backwards step in the evolution of money. George Selgin , a free banker, takes an opposing view - click here . Although he doesn't believe that Bitcoin is money, he sees its development as a fascinating turn in the evolution of money. In particular, he lauds the fact that Bitcoin production is constrained and cannot be infinite. There is a short video below where Bitcoin explain how it works.