IF YOU COULD TRUST THE AIRLINES WITH YOUR BAGGAGE, IT WOULD GO AWAY: The Carry-On-Baggage Bubble Is About to Pop: Airplanes aren’t made for this much luggage. “We know that airlines overbook their seats, then count on no-shows and rebookings to make the system work. This helps ensure that each flight will be as full as possible, but it also leads to situations where passengers must be paid to take a different flight. What if the airlines are doing the same thing with overhead bins and “allowing” more carry-on luggage than a plane can even hold? What if they’re overbooking those compartments in the hopes or expectation that some passengers won’t bother with a Rollaboard and will simply check their bags instead? If that’s the case, then the aisle pandemonium can’t be chalked up to passengers’ misbehavior or to honest confusion at the gate. No, it would mean that all this hassle is a natural outcome of the airlines’ cabin-stowage arbitrage.”

But letting them have your bags means delays and a solid chance of not having your bag at the other end. Then there’s the asinine practice, on international flights, of having you retrieve your bags, walk past a Customs officer who does nothing, and then recheck them and go through security again before connecting to your next flight. (Presumably because you’ve been in the presence of checked bags and might have retrieved a knife or something.) A carry-on can shave half an hour off the process of going through customs.