What grows one part, shrinks the other part and vice versa.
Yes? If we, say, use subsidies to reward coal plants for reducing their emissions, then coal plants will have lower costs relative to nuclear, and we'll see more coal plants and less nuclear plants than we would have otherwise, and this goes against our stated goal of reducing emissions. If we taxed emissions, then we would get the same short-term behavior but in the long run there would be less coal plants and more nuclear plants, which would aid our stated goal of reducing emissions.
Second, this is a general-purpose argument against helping anyone in trouble.
Agreed. I think this is a concern that should be taken into account whenever considering whether or not to help someone in trouble, but think that it will only be decisive in marginal cases (or cases where trouble is easy to cause or fake).
But sometimes its validity is more doubtful: for example, following this logic the SSI system for disability benefits should be dismantled immediately.
It seems obvious to me that a significant amount of 'disability' today actually is fraudulent, and the SSI system exists as it does because we haven't accepted on the social level that a growing percentage of the population is not able to contribute productive work in the modern economy. Given that SSI fulfils an actual social need that is different from its stated social need (as well as filling that need), dismantling it without fixing the problem it's been co-opted to fix seems like a mistake. If we had a guaranteed income (or negative income tax or however you want to call that solution), then it's not obvious to me that we would need SSI.
the SSI system exists as it does because we haven't accepted on the social level that a growing percentage of the population is not able to contribute productive work in the modern economy.
I don't understand. It seems to me that we HAVE accepted that on the social level and so are paying that growing percentage of the population so that it doesn't starve (or turn to crime, etc.).
Basic Income solves a somewhat different problem -- that of people not willing to work.
A post from Gregory Cochran's and Henry Harpending's excellent blog West Hunter.
The commenter Ron Pavellas adds:
The Wasserman Test.