free rider problem

Passengers who circumvent payment turnstiles are "free-riding" on the train. In economics, the free-rider problem is a type of market failure that occurs when those who benefit from resources, public goods and common pool resources do not pay for them or under-pay. Free riders may overuse common pool resources by not paying for them, neither directly through fees or tolls, nor indirectly through taxes. Consequently, the common pool resource may be under-produced, overused, or degraded. Additionally, despite evidence that people tend to be cooperative by nature (a prosocial behaviour), the presence of free-riders has been shown to cause cooperation to deteriorate, perpetuating the free-rider problem.

In social science, the free-rider problem is the question of how to limit free riding and its negative effects in these situations, such as the free-rider problem of when property rights are not clearly defined and imposed. The free-rider problem is common with public goods which are non-excludable and non-rivalrous. The non-excludability and non-rivalry of public goods results in there being little incentive for consumers to contribute to a collective resource as they enjoy its benefits as per the Tragedy of the commons.