Economics, Rights Theory

“Don’t Lean on Me!” The Ethics of the Knee Defender

knee-defender-01The “Knee Defender” is a small device that airline passengers attach to the seat of front of them to prevent it from reclining. Recently, one passenger used the device on a United Airlines flight from Newark to Denver. The passenger whose seat was disabled objected, a fight ensued, and the flight had to be diverted to Chicago where both passengers were booted off the plane.

Is using the Knee Defender unethical? Should airlines prohibit it? Justin Weinberg challenges philosophers to use their analytical toolkit to think about the situation. Here’s my take.

Who Has the Property Rights? – When you purchase an airline ticket, part of what you are purchasing is a kind of limited property right in your seat. Some of the implications of that property right are clear. You have the right to prevent others from sitting in your seat without your consent. You have the right to allow others to sit in your seat with your consent. But the emergence of the Knee Defender reveals a case in which the relevant property rights are somewhat less than clear. Is the right to recline without interference part of what you purchase when you buy your ticket? Or does the passenger behind you have a property right in his personal space that your reclining would violate? Airlines have yet to establish clear rules on this matter, so at present the question can only be answered by investigating into what we might call conventional property rights – property rights that exist as a matter of informal social practice rather than formal legal or corporate rules. Conventional rights are sometimes difficult to ascertain, which is why some (like Damon Darlin) are able to assert confidently that use of the Knee Defender is within a passenger’s rights, while others (like Josh Barro) view its use as a kind of “theft.” My own reading of the convention is in line with Barro’s. Airlines buy planes with seats that recline because they want customers to be able to lean back, just like they make seats with televisions in them because they want customers to be able to watch them. If you’re bothered by passengers around you watching television or leaning back, you’re free to ask them to stop. But you’re not free to forcibly prevent them by disabling their television or their seat.

Who Should Have the Property Rights? – Even if property rights were clearly defined, though, we could still meaningfully ask whether they’ve been defined well. Maybe things would be better – more fair, more efficient – if people didn’t have the right to recline. Suppose everybody likes to recline, but they really like not to be reclined upon. In that case, they might have a preference ranking that looks something like the following:

  1. I lean back; the person in front of me does not.
  2. I don’t lean back; the person in front of me doesn’t lean back.
  3. I lean back; the person in front of me leans back.
  4. I don’t lean back; the person in front of me does.

The best situation, from your perspective, is one in which you recline but are not reclined upon. But if most people share your preferences, this is unlikely to occur. After all, others like to recline too. More likely is outcome (3). But outcome (3) is worse, on your preference ranking, than outcome (2). You could try to move from (3) to (2) by talking to the people in front of and behind you, and maybe trying to strike up some kind of deal. But if enough people share your preferences, maybe it would just be simpler if the airlines changed their rules so as to disallow reclining in the first place. (It’s just like a prisoner’s dilemma, where Reclining = Defecting and Not Reclining = Cooperating. Even though we all might prefer to defect while others cooperate, the best institutional solution might be to prohibit defection altogether)

Better still, rather than barring reclining outright, they could simply assign the property right to the person sitting behind the recliner. That person would “own” their space, and could prevent you from reclining by withholding their consent. But if you wanted to recline much more than they wanted you not to recline, you could always pay them. It’s the Coase Theorem in action. Regardless of  how the property rights are initially allocated, as long as people are free to transact at relatively low cost, the right will tend to wind up with whoever values it more anyway.

Efficiency isn’t the only consideration relevant to determining how property rights ought to be allocated. We care about fairness, too. So, for instance, some people think that even if a market in human kidneys would be efficient, it would be unfair insofar as the wealthy would benefit from such a market at the expense of the poor. I think that critique is misguided, but you see the concern.

I can’t see how anything like that is relevant to the Knee Defender case though. People who are flying on airlines are not, as a rule, desperately poor. And the cost of being unable to afford to purchase the right from the person in front of or behind you is mild inconvenience, not death or long-term dialysis. So I’m hard pressed to think of any serious fairness considerations that could overcome the efficiency argument for allowing a market to emerge.

Here’s a different kind of worry though. Suppose we go with Baro’s proposal. You as a ticket holder have the right to recline, and if the people behind you don’t like it, they can offer to pay you to stop. What kind of incentives does that create? Well, suppose I’m the kind of person who doesn’t want to recline. But I do like money. So now I have an incentive to lean my seat back just to get you to pay me to stop. This looks an awful lot like what Robert Nozick described as an “unproductive exchange.”  And, like blackmail, there might be reason to prohibit this kind of exchange simply in order to prevent the kind of deadweight loss it involves.

How Should Property Rights Be Used? – I’ll close with what I hope is an obvious point: just because you have a right to do something doesn’t mean it’s the right thing to do. If I own a cabin in the woods, and you’re a lost hiker knocking at my door seeking shelter from a snowstorm, I have the right to turn you away. (Well, maybe). But doing so would be an awful thing to do. Similarly, if you’re a passenger on a plane and you see that the person seated behind you is a parent struggling to pacify a child in his lap, it would be, at the very least, highly discourteous of you to lean your seat back anyway. To have a property right in something is simply to have the ability to make enforceable claims on that thing, should one choose to do so. But just because you have the ability doesn’t mean you should exercise it.


  • Theresa Klein

    The fact that the airline seats are built to allow reclining in the first place, and that the controls are mounted on the recliner’s seat (not the seat behind them) indicates that the airline is granting permission to the seat occupant to recline. If the airlines wanted to grant permission to passengers in the seat behind to prevent the passenger in front from reclining, they would install seat controls to allow you to do that.

    I think the norm is that everyone really prefers to recline, and most people don’t mind it, but there are a small number of people who REALLY don’t want you to recline.

    it also might depend on the length of the flight. If it’s a 1 hour flight during business hours, that’s different than a 5 hour red-eye.

    • jdkolassa

      Also, if you’re over six feet tall in the seat behind the recliner, it can get EXTREMELY uncomfortable. Like, cutting off blood flow to your legs uncomfortable.

      • Theresa Klein

        I’m sure it’s uncomfortable for extremely fat people to sit in airline seats too. That doesn’t give them a property right to the seat next to them.

        • jdkolassa

          True – but I’m not really talking about property rights. I’m talking about disturbed blood flow and how it makes it extremely difficult to walk and can cause serious pain. It’s about not being a douchebag, that’s all.

          This is not an issue of property rights, and I’m not sure Zwolinski needed to go there. This is an issue of common courtesy.

          • Theresa Klein

            Sometimes it’s the passenger in the back who is made uncomfortable. I’ll grant that. But airline seats are pretty uncomfortable to the person in front too. And if you havn’t had a lot of sleep (which is possible if you are taking a 6AM cross-country flight), sleeping with the seat in the upright position can be really uncomfortable too. Maybe people in the back with laptops and stuff should take into consideration that the recliner might really need to catch some rest. Courtesy goes both ways. It’s not only tall people whose discomfort should be considered.

          • jdkolassa

            Having taken a direct flight from Beijing to NYC where I got no sleep whatsoever because the person in front kept reclining and I had to stumble off the plane because my legs had both suffered some disrupted blood flow, yeah, I know all about airlines being uncomfortable. You’re right, courtesy goes both ways…so please don’t recline your seat to cut off blood flow to my legs below the knees.

          • Theresa Klein

            So I’m supposed to suffer and not get any sleep on a 10 hour flight because the airline made the seats too small for you? That’s MY job?

          • jdkolassa

            I think you can be decent enough to not cause physical harm to the person sitting behind you, yes. But sure, be a heightist and just declare that because I’m tall, I must suffer, while you do not. That’s real charitable right there.

          • Theresa Klein

            Yeah, but you’re saying that *I* should suffer, for YOUR comfort. Why don’t YOU suffer for mine? You are saying the person in front should not recline to enhance the comfort of the person in back. But the person in back has no obligation to _let the person in front recline_, in consideration of _their_ comfort.

          • jdkolassa

            Shorter Theresa: tall people should suffer physical pain for the enjoyment and pleasure of shorter people.

            Got it.

          • j_m_h

            Don’t be dense. You’re buying a mass market commodity item. If you don’t like what’s produced for the masses don’t consume it.

            Or put some effort into producing a product that satisfies the market for which you’re a prime consumer. Where do you think the Big & Tall and Plus-Sized retail stores came from?

          • jdkolassa

            Oh, that’s a great comeback – wouldn’t really have worked for when I had to go to Japan for study abroad. What else was I going to consume? A long kayak trip across the Pacific?

            Don’t be dense. Simple saying “don’t consume it” or “go make your own alternative” is colossally stupid when all I am saying is “Hey, can you mind not reclining your seat back into my legs and cutting off the blood flow? Thanks.” Honestly, stop being a retard and use your brain.

            Also, seriously, making your own airline service for Big and Tall people? Who the hell do you think I am, Steve Jobs? Where the hell am I going to come up with the capital and corporate infrastructure and lobbying muscle to even make that exist in our current economy? That’s one dense comment.

          • j_m_h

            The question was not should we all be nice to one another and sometimes giving something up for the benefit of some stranger we find ourselves interacting with for some short period of time.

            The issue was about someone preventing the other person from something they clearly had the right to do and that person did not care one bit about the other person’s right.

            I’m not arguing against civility but against the claim the guy using the knee defender — and apparently claiming he will continue to do so — rather than seeking the agreement with the other person and respect that person’s decision. The decision is not his (or yours) to make. The is what I’m taking exception to in your responses.

            In fact I would argue that the civil approach is the correct way to go and that it’s actually largely orthogonal to the question, or at least the analysis, offered by Matt and invoking property rights. If we stay with the PR analysis, however, your arguments simply don’t apply because you seem to keep ignoring the rights as they clearly exist.

          • jdkolassa

            I am not and have never in any of these comments been defending the use of the knee defender. That’s clearly illegal.

            Maybe that wasn’t clear, but in no way am I condoning the use of that device.

          • Theresa Klein

            And you’re saying that short people should have to suffer sleep deprivation for the comfort of tall people sitting behind them.
            Yeah, it may be polite to not recline into your knees, but also sometime, I might really need some sleep, and given that I paid for the seat, maybe you SHOULD suffer a little bit so that I can do that. I didn’t ask to be seated in front of you, and giving up the ability to recline might actually impose a significant cost upon me.

          • jdkolassa

            As long as we’re clear about your bigotry towards tall people and that you actively want us to suffer for your own personal enjoyment, fine. Doesn’t seem very BHL, but then you’re not required to be to comment here…

          • jdkolassa

            Also, for the record, I am not saying you have to suffer for my comfort. I am saying, “Hey, maybe I can just ask you to stop reclining my seat into my leg. Can you give me just a couple of inches and call that a deal?”

            You somehow think a polite request like that is causing physical harm to you. That’s just nuts.

          • j_m_h

            Yes, and as I say in my post just prior to this, I see that as a better solution to the situation than looking to some complex property rights review. It’s really not that complicated — that said the guy using the device still comes off looking like a total jerk and acting in a completely uncivil way.

      • martinbrock

        Is freedom from this discomfort a privilege of the short?

        • jdkolassa

          Perhaps. But I mean, when people can cite thrombosis as a serious medical condition as a result of this, don’t you think that warrants just a bit more courtesy?

          Ultimately the real solution is to stop pushing passengers into the planes like cattle and give a little more legroom, but the airlines will never do that. Considering their margins, it’s understandable.

      • j_m_h

        And is solved buy renting a seat with more spacing between it and the one in front of it.

        • jdkolassa

          So if the person in front of you is causing physical harm to you, because the seat is owned by the airline, it’s okay?

          • j_m_h

            Then you speak with the airline about moving to a different seat. If you already know you are not a suitable flier for economy or even business class (where it’s available) then perhaps flying in those classes is not a suitable option for the person and alternative modes of transportation must suffice.

            Or are you saying the rest of us need to subsidize “your” personal characteristics?

          • jdkolassa

            Who is talking about subsidizing my choices? I’m talking about not causing physical harm to another human being. Since when did we throw that concern out the window?

            And as for price, what if you are on a budget and can’t afford first class, therefore you must travel in economy? There are a great many factors to consider which you appear to not want to.

          • j_m_h

            You are calling for others to subsides your travel services because you don’t want to incur the costs of travel services that meet your personal needs. You’re a special case but insist that you should not have to make the payments those special needs require.

            You make no case whatsoever for why we need to socialize the cost of your flying.

            I largely reject your claim of harm — you might be uncomfortable but that’s not an actionable harm, especially given that you’re aware of this going in and don’t do anything to avoid it (which includes taking some slower form of transport).

          • jdkolassa

            Again, when I was going from New York to Japan, what the hell was I supposed to do? Kayak across the Atlantic?

            I’m just asking people not to be dicks and be considerate of people around them. Maybe you should pull your nose out of an economics textbook and engage with the real world for once.

          • j_m_h

            I don’t live within the econ text books. I understand the arguments and subject pretty well but that’s not where I liver or even spend much time thinking specifically about.

            That said, the basic thought experiment offered here was construed in the property rights and costs allocations & distributions (re Coase Theorem) so engaging the logic on that basis is not out of order (see the several post in this blog about the use of hypotheticals/though experiments and the frustration of those who then want to change the game to make their statements).

      • jacksmind

        And siting up straight for long flights can be EXTREMELY uncomfortable–I mean swollen legs and thrombophlebitis uncomfortable.

    • Aeon Skoble

      “The fact that the airline seats are built to allow reclining in the first place, and that the controls are mounted on the recliner’s seat (not the seat behind them) indicates that the airline is granting permission to the seat occupant to recline”

      • genemarsh

        That. Don’t do that.

    • adrianratnapala

      Yes, the airlines define the amount of reclining that is allowed by the calibration of the seat. But this brings up a point: any Coaseian bargain can only work in the direction of less reclining. Dwarfs have no way to sell their space to the would-be recliner in front of them. Somehow I don’t think that’s a very big issue though.

  • martinbrock

    Pricing the shared space somehow is conceivable, but I’d ask a steward/ess to find someone who doesn’t want to recline and will switch seats with me. I suppose s/he’s more likely to ask the knee defender to remove the device, but I’m also willing to change seats if necessary. Conflict over the disputed space also has a cost, which seems to be the Coasean point.

    The guy in the picture, with his knees propped on the seat in front of him, is not obviously trying to prevent the person in front of him from reclining, particularly since he seems to be reclining himself. I sometimes find this position more relaxed myself, and it can be more comfortable, not less so, with the seat in front of me reclined, but people sometimes don’t like the sense that I’m pressing on their seat. They may think that I object to their reclining or am trying to prevent it, but I’m not; however, I never communicate my intention, because the negotiation doesn’t seem worth the effort.

  • Steven Horwitz

    One other point: some airlines, like Spirit, do not have reclining seats. That is also some evidence that the decision to give the passenger the right to recline is a conscious one by the airlines.

    Irony: the guy who caused the problem on the United flight ended up flying on Spirit for the rest of his trip. His use of the Knee Defender in Economy Plus on United with a 35″ seat pitch led to him flying on no-recline Spirit with a 28″ seat pitch. Nice job buddy.

    And btw, the guy? Complete jerk:

    • Theresa Klein

      What a whiner. If someone recline their seat in front of me so that I can’t open my laptop, I just put it on my lap instead.
      This guy explicitly reneged on his promise that he would remove the knee defender by shoving the seat forward and shoving it back in.
      I don’t blame the woman at all for throwing a drink in his face at that point.

      • Tedd

        I can’t go along with that. I agree completely that the story strongly suggests it was mostly the fault of Knee Defender Guy, but throwing a drink in someone’s face is over the top, period. It may not be very violent, but it still crosses that threshold and so can’t be considered acceptable.

    • jdkolassa

      On the one hand, yeah, a jerk.

      On the other, she could have been more diplomatic, and definitely didn’t need to slam her seat back all the way like that. I’m not sure how accurate his comments about his laptop are, but I wouldn’t be surprised if they were true.

      • Theresa Klein

        I don’t think he bothered to check to see whether she slammed it on purpose, or just because when he released the knee defender, the seat was suddenly released.
        Anyway, wouldn’t you be a little annoyed if you thought your seat was “broken” and then found out that the person behind you deliberately sabotaged it to prevent you from reclining?

        • jdkolassa

          I would be annoyed, but I

          A) Would not have slammed the seat back so damn hard
          B) Would not have thrown my drink in his face.

          It’s not worth that much.

          • Theresa Klein

            She threw her drink in his face AFTER he slammed her seat back forward again, and jammed the knee defender back in.

          • jdkolassa

            From what I read, she slammed the seat back first, which led him to slamming her seat forward.

            Not defending either here, but come on.

      • Tedd

        I really doubt that the passenger ahead slammed her seat back. Most likely, the Knee Defender allowed enough motion that the latch was still released, and she was still sitting in the seat. So when Knee-Defender Guy removed his device her seat just fell back. It sounds like a case of both jerkiness and stupidity. He left his laptop on the table while he pulled the Knee Defender out, for heaven’s sake!

  • Salem

    The airlines are in control of what is and is not permissible on their flights. Using the “knee defender” is against the rules at all of the major US airlines. Even if reclining is rude (of which I’ve never been persuaded), it’s clear that using the “knee defender” is not a valid response.

  • Sprudlum

    My knee jerk response to this problem is that more people should travel by train.

    Gives you more time to philosophize on serious philosophical problems too.

    • jdkolassa


  • j_m_h

    The Coasean assignment of rights has already been done: the seat is designed with the ability to recline and the airline tells everyone when it’s okay to recline their seat.
    If you don’t want the person in front of your reclining off the bribe.

  • j_m_h

    I think in a rental situation such as a plane flight the applicaiton of property rights theory too seriously is potentially dangerous — the actual property rights exists and remains with the airline and there’s just a very short term rental agreement for the passenger. Treating the renter as the owner is okay for some analysis but not for all analysis.

  • JoshInca

    Your premise is wrong because an airline ticket does not provide you with property rights, in any way, over any space which you are assigned by the air carrier. In fact, you’re not even leasing that space.

  • Tedd

    I like the conclusion (that the right to do something does not make it right to do). I often wonder if discussions about rights, in general, go off the rails because one or another of the parties involved doesn’t understand that.

    Regarding seat reclining, it seems like a no brainer. You buy the ticket believing that the seat will have a recline feature and that therefore you will be allowed to use it. You also buy the ticket believing that the person seated in front of you will have the same feature and the same right. It’s simply not plausible to argue otherwise, and the Knee Defender is clearly a violation of the rights of the person seated ahead. But if the airlines want to have some seats without the recline feature and build that into the pricing model, I’d be perfectly fine with that.

  • Dreadful. This guy teaches? Whom? Why?

    Suppose my son were attending his Hillbilly institution and he read this shite- what would be my response?-

    1) Who Has the Property Rights? – When you purchase an airline ticket, part of what you are purchasing is a kind of limited property right in your seat.

    WRONG. Sonny boy, if you wannna be a lawyer and pay me back for all the money I spent on you, tell this so called “prof’ to f.o.
    There is LITERALLY no scenario where a rational airline would make the proffer this cunt assumes. Why? Because, he’s a stupid cunt called Zwolinski. He tried to ban me posting here. Why did he fail? He so stooooopid? I guess. yeah. Fuck this makes me look like the bad guy.
    2) Is there a Substantive solution?
    Urm…yes. There’s just a few hundred on a plane so a fucking substantive solution does too exist- which is why property rights don’t get Zwolinskini distributed.
    How fucking stupid is this cunt?
    3) Hello, this is Ronald Coase from 1930, could you please pick up the fucking phone- Matt, darling, you tried to fuck with me but I phoned your superiors didn’t I?, you worthless cunt- why don’t you learn some Econ or Phil Logic or Maths you worthless cunt?

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