I'm confused. Aren't basic income and negative income tax equivalent? x-m(x-c)=x-mx+m*c Of course, that gets more complicated when it isn't a flat tax, but I

I'm confused. Aren't basic income and negative income tax equivalent? x-m(x-c)=x-mx+m*c Of course, that gets more complicated when it isn't a flat tax, but I would think that for those in the lowest tax bracket, it would be equivalent, because within that bracket it would be flat?