Alternate incentives
Sometimes, it would be good for somebody to do a thing, but the benefits go mostly to random strangers: there's no way for the agent to capture the value they'd create. In these cases, the classic solution is for the government to reward people for doing the thing / punish people for not doing the thing. Some examples:
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Installing pollution control doesn't benefit the factory that installs it. Therefore, the government should punish people who pollute (e.g. via a Pigovian tax); else, everybody (except philanthropists) would do it.
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Some vaccines (like Tdap) can be pretty miserable, and you get most of the benefit from herd immunity, so there's a free-rider problem. Therefore, the government should pay people to get it (or, equivalently, fine them for not getting it); else, nobody (except philanthropists) would do it.
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"Not stealing" doesn't benefit the person who does it. Therefore, the government should punish thieves; else, everybody (except philanthropists) would do it.
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Research into what public-health measures are effective doesn't really benefit the researchers (because there's no way for them to effectively sell the knowledge they produce without a massive free-loader problem). Therefore, the government should pay people to do it; else, nobody (except philanthropists) would.
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Similarly, creating art doesn't really benefit the artist (because there's no way for them to effectively sell the art they produce without a massive free-loader problem; copying art is easy!). Therefore, the government should pay people to do it; else nobody (except philanthropists) would.
So... there's another solution, that doesn't involve the government directly incentivizing Doing The Good Thing, but instead changing other people's incentives to make it easier to capture the value produced by Doing The Good Thing. And, sometimes, this other approach might be the right tool for the job: intellectual property law is definitely imperfect, but consider the alternatives of "only philanthropists create art" or "artists need to worry about losing funding because a bureaucrat thinks their boss thinks their boss thinks their boss thinks Trump wouldn't like it."
Somehow I'd never explicitly noticed the existence of this other approach.