The Wealth of Nations by Part 5 Chapter 2 Page 112

When it is not so proportioned, but is the same upon all dealers, though in this case, too, it is finally paid by the consumer, yet it favours the great, and occasions some oppression to the small dealer. The tax of five shillings a week upon every hackney coach, and that of ten shillings a year upon every hackney chair, so far as it is advanced by the different keepers of such coaches and chairs, is exactly enough proportioned to the extent of their respective dealings. It neither favours the great, nor oppresses the smaller dealer. The tax of twenty shillings a year for a licence to sell ale; of forty shillings for a licence to sell spirituous liquors; and of forty shillings more for a licence to sell wine, being the same upon all retailers, must necessarily give some advantage to the great, and occasion some oppression to the small dealers.