The problem in this world is to avoid concentration of power - we must have a dispersion of power. - Milton Friedman

The major disadvantage of the proposed negative income tax is its political implications. It establishes a system under which taxes are imposed on some to pay subsidies to others. And presumably, these others have a vote.

There's a smokestack on the back of every government program.

The existence of a free market does not of course eliminate the need for government. On the contrary, government is essential both as a forum for determining the 'rule of the game' and as an umpire to interpret and enforce the rules decided on.