Why do people want bitcoin why they can do business in that? For privacy he said. They have a good medium of currency, which is called the dollar, "breaking it" on the "secret" bitcoin usage cases, "it has to get out of existence". 

https://cointelegraph.com/images/725_Ly9jb2ludGVsZWdyYXBoLmNvbS9zdG9yYWdlL3VwbG9hZHMvdmlldy9iMGU4N2M4NDg4YTc2ZmNhZjczNGQ3MjNjNTE1ZTZjYi5qcGc=.jpg

He has addressed the Bloomberg TV audience during the annual program in Davos, Switzerland, the professor and Nobel laureate said. As an economist, Joseph Stieglitz line is involved in promoting the value of fat currency, its current 2018 World Economic Forum has given negative feedback to Bitcoin so far. 

Source - https://cointelegraph.com/news/regulate-it-out-of-existence-stiglitz-and-swiss-bank-bash-bitcoin-at-davos