I bet they would have on European discounter Ryanair: The renowned cheapskate airline allows passengers a just a single, small carry-on bag (22 pounds or less) or one purse or one laptop or one coat or one shopping bag -- well, you get the idea.
Ryanair is strict -- and maybe the U.S. airlines should be too -- at least when it comes to the size of a carry-on. Sure, many airlines do have limits, but they don't evenly enforce them and it doesn't help that each aircraft has different bin sizes. Fees might help, as I note in my list of pros and cons.
I think carry-on fees will fly if we all derive the same benefit from them, meaning we all get to take up the same amount of space -- and enter, the baggage police.
To make this really fair, I can see a carry-on fee leading to a "universal bag size" -- one that easily fits into the bins of big jets, and possibly even smaller regional jets. Besides, if bags actually fit, it could mean less waiting in the aisles, which could improve on-time departure statistics -- and maybe allow passengers the convenience of boarding later. Bonus: you'd be more likely to find a bin that's actually in the vicinity of your seat.
This one's easy: No one wants to pay for something that used to be free. On the other hand, TV used to be free, too, but we sure got used to paying those cable and satellite bills, didn't we?
Another "con" to consider: airlines don't like bad PR. Which carrier wants to be the first to endure the brunt of terrible press, not to mention the constant snark from the late-night talkshow hosts.
Finally, who's going to be the carry-on cop? Who will measure and weigh -- be judge and jury? I'm not sure, but if airlines are strict in the beginning, I suspect we'll all fall in line.
We may not have a choice.
This work is the opinion of the columnist and in no way reflects the opinion of ABC News.
Rick Seaney is one of the country's leading experts on airfare, giving interviews and analysis to news organizations, including ABC News, The New York Times, The Wall Street Journal, Reuters, The Associated Press and Bloomberg. His Web site FareCompare.com offers consumers free, new-generation software, combined with expert insider tips to find the best airline ticket deal.