I recently flew with El-Al from England to Israel. I am tall and the flight was not full so I moved to a seat that has more leg room. If I would have requested this seat when I booked my flight I would have had to pay a higher price for this seat. However, since it is not such a long trip, I didn’t ask for a special seat in order to save money. However, I figured if no one is sitting there anyway I might as well sit there and be more comfortable. Do I owe the airline anything and even if not, was my action proper?
At first glance it would seem that everything you did was fine and you do not owe anything since the rule is that ze nehene veze lo choseir potur – if the owner did not bear any loss, the one who derived benefit from his possessions does not need to pay for the benefit he derived. The P’nei Yehoshua (Bava Kama 20A) explains that the reason he doesn’t need to pay is because it is an attribute of Sodomites to prevent others from benefiting from their possessions even when they bear no loss. Since we are supposed to shun their behavior and to allow others to use our possessions if we do not suffer a loss, the one who used them without permission is not liable. However we will see that there are a number of reasons why this does not apply to your case.
The first reason is that it is only if the owner suffers absolutely no loss the one who benefited is not liable. However, if the owner suffers even a slight loss, according to most poskim including the Shulchan Aruch (CM 363, 7) (the exception is the Rama) the one who benefited must pay for the entire value of the benefit that was derived. The reason is that in principle one should always have to pay for the entire benefit he derived from another person’s possessions. It is only if there is absolutely no loss that since it is midas Sodom the payment is waived.
An example brought in the Gemara (BK 20B) where one is liable is if someone lived in another person’s vacant house which was never rented to anyone. The Gemara rules that even if the entire loss that was suffered by the owner was just that his walls were slightly blackened the resident must pay the full price that the house was worth as a rental because the owner sustained this minor loss.
Moreover, we see from the Gemara that the one who benefited must pay must pay for his benefit even if he only caused a loss to the owner in a passive manner. This can be seen from the Gemara’s (BK 20B) ruling, as it was understood by Tosafos and many other Rishonim, in a situation where one person has a field that completely surrounds another person’s field. These Rishonim rule that if the owner of the outer field builds a wall that surrounds his field and, consequentially, also the inner field, the owner of the inner field must pay a percentage of the cost of the wall even if he never asked for it. The reason is because the presence of the inner field caused the fence that enclosed the outer field to be more expensive because it had to be longer to enclose also the area of the inner field. Thus even though the owner of the inner field did nothing active to raise the cost, since his mere presence causes a loss it obligates him to pay for his entire benefit. Some poskim (Chochmas Shlomo siman 363) derive from Tosafos (Kesubos 30B) that even if the loss to the owner is not even the value of a peruto it suffices to require the one who derived benefit to pay in full for his benefit.
The Noda Biyehuda (Tinyono CM 24) was asked about a publisher who, after he set type to publish a customer’s sefer which was a Gemoro with Rashi and Tosafos and his customer’s commentary, did not dismantle the type. Instead he used the type (which had been set at the expense of his customer) to publish a Gemoro with Rashi and Tosafos without his customer’s commentary. The Noda Biyehuda ruled that the publisher must pay his customer for the savings he had from not having to reset type since publication of his Gemoro would cause a decline in his customer’s profits. He reasoned that some people who would otherwise have bought his customer’s sefer would no longer do so since they would have bought the customer’s sefer since it contained the Gemoro with Rashi and Tosafos and now they would no longer do so. Thus, we see that even causing a loss in profits suffices to require the one who derived benefit to pay for his benefit.
Having established the broad sense of the loss that suffices in order to require one to pay for the benefit that he derives, we can consider your situation. Modern day poskim (see Chukas Mishpot of Rav Peretz, for example, who discusses riding for free on a partially empty bus) note two losses that are suffered by the carrier as a result of your use of the vacant seat.
One loss is that if other people act in the same manner as you did, many people will not pay the higher price for these seats since they will take into account the fact that they may be able to get the seat for free. As we saw, the Noda Biyehuda ruled that even loss of potential income is treated as a loss. The loss you are causing is a slightly additional chiddush because your action alone will not directly cause a loss of income but if it is prevalent it will definitely cause a decline in income. This is one reason why the poskim classify your benefit as a benefit that entails a loss.
A second loss to the airline is that in order to fly, the airline spends money on fuel, salaries and much else. Without these expenses the flight could not take place. Since the airline spends in order to benefit everyone who flies with them, this expense is necessary in order to enable all those who fly to benefit. Therefore, all those who benefit from the flight must pay for the flight, at least as one who benefited from another person’s loss.
The halocho (CM 264, 4) is that even if a person spends money in order to benefit himself and another person the second person must pay for his benefit because halocho views the expense as having been made in order to benefit both individuals. The example discussed by the Ramo is of someone who was imprisoned and spent money (lawyers, bribes) in order to be released. The Ramo rules that if at the time of the expenditure he had in mind a fellow prisoner, the fellow prisoner must share in his expenses. Therefore, since the airline spent money in order to benefit all the passengers on the flight, they must all pay the fees charged by the airline.
In your situation, some might argue that you already paid for a seat on the flight and the extra benefit you derived was not related to the airlines’ expenses since as far as expenses are concerned they are the same for a more comfortable seat as for a less comfortable seat. However, this argument is faulty because the higher prices that are charged for these seats are part of the airline’s way of covering expenses and making a profit. What the airline is really doing is that it is dividing its expenses among the passengers based partially on the comfort of its passengers.
This is similar to the ruling of the Shulchan Aruch (CM 272, 15) (based on the Gemara (BK 116B) that if a guard was hired to protect a convoy from bandits the expense is divided based on the value of the goods that each individual is transporting.
In conclusion, in the future you should ask for permission to move to a more comfortable seat. As for this time, unless you can find out that the airline has a policy not to charge it would seem you are liable. We will continue next time with an additional reason and also discuss whether you were allowed to move.