Interesting piece here from Slate's Farhad Manjoo on why AT&T should dump unlimited data plans and end what he calls the "iPhone all-you-can-eat buffet." He notes that: "The typical smartphone customer consumes about 40 to 80 megabytes of wireless capacity a month. The typical iPhone customer uses 400 MB a month. AT&T's network is getting crushed by that demand." Because "some iPhone owners are hogging the network" and causing "a slowed-down wireless network," Manjoo recommends a congestion pricing model as a method of balancing supply and demand:

How would my plan work? I propose charging $10 a month for each 100 MB you upload or download on your phone, with a maximum of $40 per month. In other words, people who use 400 MB or more per month will pay $40 for their plan, or $10 more than they pay now. Everybody else will pay their current rate--or less, as little as $10 a month. To summarize: If you don't use your iPhone very much, your current monthly rates will go down; if you use it a lot, your rates will increase. (Of course, only your usage of AT&T's cellular network would count toward your plan; what you do on Wi-Fi wouldn't matter.)

To understand the advantages of tiered pricing, let's look at AT&T's current strategy of spending billions to build more network space. Why won't this work? For the same reason building more roads doesn't reduce traffic--more capacity increases the attractiveness of driving, which brings a lot more cars to the road, which leads to more gridlock.

Congestion pricing and metering is something I've written quite a bit about here in the context of wireline broadband (1, 2, 3), but Manjoo is equally correct that it could be applied for wireless data plans. It has the added value of taking pressure off lawmakers to impose Net neutrality regulation since pricing of the pipe becomes an effective substitute for most other forms of network management. In other words, price, don't block bandwidth-hogging customers and applications. The problem, Manjoo explains:

Of course, users would cry bloody murder at first. The traditional criticism of tiered pricing on telecommunications systems is that it's too expensive and too annoying for customers; people don't know how much they're spending during the month, and then they're smacked with huge bills. Most Internet companies aren't big fans of tiered pricing, either. They worry that adding a meter to Internet time will reduce people's propensity to try out new stuff online--killing innovation on the world's most innovative communications platform.

But tiered pricing on the iPhone doesn't have to be onerous. I'd call on AT&T to create automatic tiers--everyone would start out on the $10/100 MB plan each month, and your price would go up automatically as your usage passes each 100 MB tier. The key to implementing this policy is transparency. The phone should have an indicator--sort of like the battery bar--that changes color as you pass each monthly tier. That way, people can adjust their usage to suit how much they'd like to pay--limiting surfing if they approach the next tier, or deciding to press on if money's no object.

What Manjoo is getting at here is what economists refer to as a "Ramsey two-part tariff." A two-part tariff (or price) would involve a flat fee for service up to a certain level and then a per-unit / metered fee over a certain level. It is widely regarded by most economists as the most efficient and pragmatic solution to high-fixed cost, low marginal cost investment conundrums. It's hard to know where the demarcation should be in terms of where the flat rate ends and the metering begins, but that's for market experimentation to sort out. But the clear advantage of this solution is that it preserves flat-rate, all-you-can-eat pricing for casual to moderate bandwidth users and only resorts to less popular metering pricing strategies when the usage is "excessive," however that is defined.

Some companies have shown signs of embracing it, but few have formally adopted congestion pricing or metering. Worse yet, some of the regulation-happy activist groups in D.C. (like the neo-Marxist charlatans as the UnFree Press) have already made ridiculous accusations that metered pricing is somehow "unfair" when, in reality, it is the fairest system under the sun. There's even been legislation introduced by Rep. Eric Massa (D-NY) that would forbid the practice through the imposition of Internet price controls. Foreclosing experimentation with such innovative pricing schemes would be a real innovation-killer.

I hope we get there eventually for all high-speed data services, whether we are talking wireline or wireless. Although I generally try to be agnostic about business models, I think this one is worth doing a little cheerleading for because it helps take regulatory pressure off the marketplace. Pricing also acts as a signal for others innovators and entrepreneurs in the market regarding how to adjust investment strategies or enter new markets.