This paper uses laboratory experiments to compare the performance of a quantity collar like the one under consideration by the EC with the types of price floors and caps that have been implemented in US regional cap-and-trade programs. We assess how the different policy instruments affect production, net social surplus, and the variation of market price from optimal levels. The attached pdf is a working paper from 2015. The final paper was published in 2016 in the Journal of Environmental Economics and Management, Vol. 76, pp. 32-50.