Scholarly interest in personalized pricing is growing, and with it confusion about what, exactly, empowers a firm to personalize prices to its customers. You might think that the key is information. So long as you know enough about your customers, you can tailor prices to each. That is, however, incorrect.
No matter how much you happen to know about your customers—indeed, even were you to have a god’s total information awareness regarding each of them—you would not be able to charge personalized prices if you were to operate in a perfectly competitive market. Competition trumps information.
That is because in a perfectly competitive market there are always other sellers available who are willing to charge a price just sufficient to make the marginal buyer in the market willing to stay in the market and make a purchase. If there weren’t, then there would be a chance that the marginal buyer would not be able to find a price that he is willing to pay, and so would not buy, and then the market would no longer be perfectly competitive. For the perfectly competitive market is one in which competition leads to a price at which the marginal buyer and seller are willing to transact.
And so any attempt you may make to personalize a higher price to your inframarginal customers—the ones who are in principle willing to pay a higher price than the marginal buyer—will be met with scorn. Your customers will find those other sellers offering prices keyed to the willingness to pay of the marginal buyer and will purchase from those sellers instead at that marginal-buyer-tailored price.
Thanks to this effect, all buyers will transact at the same, marginal-buyer-tailored price, and so we can conclude that in a perfectly competitive market, price will always be uniform—and uniformly equal to the price at which the marginal buyer and seller transact. (More here.)
It follows that while information is a necessary condition for the personalizing of prices, it is not a sufficient condition.
You also need a departure from perfect competition, which is to say, you need: monopoly. Or at least a hint thereof.
I have argued that personalized pricing is one way to break the iron link between redistribution and inefficiency. When you personalize prices, you can personalize one price to the marginal buyer, ensuring that he stays in the market and the market is efficient, and whatever other prices you wish (within limits) to inframarginal buyers, enabling the redistribution of wealth. But it is important to remember that information on buyers is not alone enough to make this possible. The seller must be a monopolist, too.
Thus the use of personalized pricing as a tool of social justice directly conflicts with the mindless “big is bad” rhetoric that one finds today in certain corners of the progressive movement.
To redistribute wealth at the market level you need to start with big.
And then discipline big’s pricing behavior.