Coercion and selective benefits are used by interest groups to address what issue?

Explain collective action problems and free riding, and how groups get around these problems through benefits of participation (i.e., solidary benefits and purposive benefits), coercion, and selective incentives.

collective action problem; situation in which members of a group would benefit by working together to produce some outcome, but each individual is better off refusing to cooperate and reaping benefits from those who do the work; one individuals efforts will not make a big difference; individual is better off free riding, can not do any work but still enjoy successes of group; even when people agree something would be good, cooperation isn't easy or automatic

free riding; relying on others to contribute to a collective effort and not participating on ones own behalf, but still benefiting from the groups successes

mechanism to promote cooperation: benefits from participation, coercion, selective incentives

soldiery benefits-satisfaction derived from the experience of working with like-minded people, even if the groups efforts do not achieve the desired impact 
purposive benefit- satisfaction that comes from working to achieve a common goal
coercion- requiring participation; ex. labor unions require union dues as condition
selective incentives- benefits only given to members of an interest group
hope this helps.