What policy ideas do you think are both tractable and high impact?

No strong opinion on re-posting the same question, but would rather previous versions not be deleted to re-post them if they got answers:

https://web.archive.org/web/20230103122818/https://forum.effectivealtruism.org/posts/85EmFxDmcQBhnrABt/what-are-some-high-impact-policy-ideas-that-you-consider-to

Don't have time to write up the full arguments why, but housing and pandemic preparedness would be my top two. Immigration is less tractable but highly valuable.  This is from a US perspective.

Globally, I think that promoting women's rights in many developing countries is a potentially high impact activity. 

For developed countries, my favorite policy is unemployment benefits contingent on unemployment level. When the economy is heated, benefits are contracted, when turns recessive, they are expanded and lengthened.

It is good for people and for economic stabilization.