In a country the USA, I'm not sure that consumption really is proportional to income. When you are poor, almost all of your income is spent on necessities. Everything is on such a day-by-day hand-to-mouth level that many things end up costing more (i.e. going to the emergency room instead of the family doctor). This is because you do not have the funds for insurance, to plan ahead, to buy or rent a house (paying weekly rates at hotels really adds up), or to buy quality & long-lasting items.
As you move up the scale, possibly the first shift is increased expenses on diet. It's only at the higher income levels that people actually start saving. It's for this reason that I've always seen sales tax as regressive. CL Christopher J Wells wrote: > If consumption is proportional to income (which seems reasonable) then the > greater consumer pays the greater tax. > > Poor people are probably consumers of fewer goods so it seems reasonable > that they would pay fewer taxes.
