take the example of carbon emissions reductions from coalfired power generation with a carbon tax the generator would choose an efficient leastcost mix of technical abatement eg more efficient boilers and reductions in the output of electricity to achieve the intended level of emissions with a quantitybased standard instead generators would overinvest in technical abatement and underinvest in output reductions thus selling more electricity than with a carbon tax this is because in the example of the standard case inframarginal emissions are costless and only the last unit of emissions elicits compliance what looks like an advantage ie more electricity sold at the same amount of emissions is in fact an economic disadvantage by levying a pigouvian tax the government could have generated a higher value for the overall economy than the added surplus for the electricity customers resulting from the standard