It's my understanding that a sales tax is one of the better revenue sources from a fiscal policy perspective. Its primary downside is the difficulty of collect

It's my understanding that a sales tax is one of the better revenue sources from a fiscal policy perspective. Its primary downside is the difficulty of collection, but otherwise the incentives are good. On the other hand, something like a capital gains tax discourages investment. (Not saying that shouldn't exist, just that it's not clear it's superior to a GST.)