I don't think bitcoin has bad effect to the economy of a country, rather I can say that there is a negative because if many bank investors withraw their half of investment in a bank and put in bitcoin the income that will in and out from and to them will is not subject to the tax law but only for this. The advantage, it gives a chance to a jobless someone to have a work, in this case every income that goes into his pocket and use it to buy is a great help for the economy of his/her country if he/she is jobless this will be a great burden of government.