Public goods, as economists use the term, are “nonrival” (one person's consumption does not make it unavailable for others) and, typically, “nonexcludable” (if the good is provided to one person, others cannot be prevented from enjoying it as well). The classic example is the lighthouse, whose warning light goes out to and benefits all ships. Economists devote special attention to public goods because markets do not deliver them efficiently. Rational, self-interested actors realize that if anyone else provides this good, they can have it without paying for it. The incentives favor “free riding.” Others, however, see the same opportunity and so public goods go underprovided. There is thus a strong case for collective action to furnish public goods. Where collective benefits outweigh the costs of provision, government action can make society as a whole better-off.