Gauranteed Annual Income

The topic of a guaranteed annual income came up in class this week. This concept comes up  in Canada, as well, every once in a while. In place  of all social assistance payments such as welfare, unemployment insurance, disability payments and pensions, every citizen would be paid an annual income from the federal government. If a person didn't need the money, it would be taken back by the government at income tax time. What do you think?