Offering to pay the passenger in front of you to keep her from reclining her airplane seat is an example of

The answer is: a Coasian solution to an externality situation

Coasiaon solution refers to a way of thinking that people have that make them willing to have some sort of economic expense in order to solve an external problem rather than having to endure a certain level of discomfort.

This type of behavior is much more common if the 'expense' is considered as a low transaction cost and both parties involved will both gain some sort of value from the exchange.