[catskul2]

Yes. Even in Canada they already have something similar with their carbon taxes. IIRC, tax is collected all year and returned at the end based on income rather than consumption.

Not sure if it would technically be considered a negative tax, but the effect is similar.

[StreetChief]

I was thinking more along the lines of my purchase price is x + y tax + -z tax. A return eventually isn't quite the same, but maybe it's effectively the same.