> If there isn't different resource.. There's always a different resource that you can substitute if you look widely enough at the big picture. E.g. for party

> If there isn't different resource.. There's always a different resource that you can substitute if you look widely enough at the big picture. E.g. for party balloons, sure, maybe only helium works, but it's only there as an entertainment option, of which there are many substitutes. Same for say, helium for scuba diving—sure, there might not be an alternative, but the purpose of most forms of scuba diving may be fulfilled by alternatives (submersibles / robots / snorkeling depending on whether for practical or enjoyment purposes). A tax would drive people to fulfilling the wider economic and societal need without using a product that requires helium. > which is how they actually failed Cap and trade did not 'fail', it succeeded in capping emissions at the number of credits + allowances. If you want to reduce emissions more, then reduce the total quantity. Price targeting and quantity targeting are just different ways of stating what your goal is.