Once upon a time, Chicago to New York was a cheap rail fare, whereas the much shorter trip from Chicago to Peoria was expensive, because in a dense rail network there were lots of ways to get from Chicago to New York, and therefore lots of competition on that route, whereas there were only a few ways to get from Chicago to Peoria, and therefore much less competition. The big city people who rode Chicago to New York had more money than the small city people who rode Peoria to Chicago, but the big city people paid lower fares, because the big city people benefited from competition.
Competition gave the big city folk alternatives, and that strengthened their bargaining power vis a vis the railroads. The lack of competition denied the small city folk alternatives, and that reduced their bargaining power vis a vis the railroads. But the changing of alternatives is taxation.
Suppose instead that rail competition were somehow equal in both markets, but the government were to tax small city riders by a certain amount and redistribute that amount of money to the big city riders. The tax would effectively drive up the fare paid by the small city riders and drive down the fare paid by the big city riders, achieving the same result as did the unequal levels of competition on the big and small city routes. Inequality in competition is tantamount to inequality in pricing, which is tantamount to tax and transfer.
Put another way, the presence of competition on the big city route and absence on the small city route caused the railroads to collect a large share of their revenues from small city riders. Small city riders subsidized big city riders, in a sense. The railroad acted as a kind of taxing authority, redistributing from small city riders to big city riders, but the railroad’s tax policy was determined by the competitive environment, not the railroad itself, by the presence of competition on the big city route and the absence of competition on the small city route.
Flip the competitive configuration — make the small city route less competitive than the big city route (perhaps by allowing cartelization of service providers on the big city route) — and now the big city riders will contribute a larger share of the railroad’s revenues. Now the big city riders might be said to pay the subsidy and the railroad to be taxing the big city riders for the benefit of the small city riders.
Depending on how antitrust divides up markets and goes about promoting competition in them — as I discuss briefly in another post — the competitive terrain created by antitrust represents a tax system and a specific set of distributive results.
From this perspective, if your goal is to redistribute wealth, you want more competition in some markets — the ones inhabited by the poor — and less competition in other markets — the ones inhabited by the rich. That’s just the kind of policy that progressives advocate: antitrust for big firms, cartelization for workers and small businesses.
Note that this is not an argument about the ability of competition to force a particular distribution of surplus within a market, between buyers and sellers. This is about the ability of antitrust to alter relative outcomes in different markets by altering relative levels of competition. This is about how antitrust makes price discrimination possible, and how that price discrimination redistributes, even when the different prices charged are charged by different firms in different markets.