Yes, I understand all this which is why I was hoping there was a good study or something done on the matter. Junk mail accounts for 48% of all mail volume, but

Yes, I understand all this which is why I was hoping there was a good study or something done on the matter. Junk mail accounts for 48% of all mail volume, but only 26% of revenue. What would be the effect of increasing the cost of junk mail until its volume decreased by half? You'd see a 24% decrease in mail volume, but less than a 13% decrease in revenue. Would this decrease in volume facilitate cutting "fixed costs" like labor? Or are the costs truly fixed? If so, is that for business reasons or due to congressional mandates or what?