I've seen several people on Less Wrong recommend Mencius Moldbug's writings, and I've been curious about how he became so popular here. He's certainly an interesting thinker, but he's rather obscure and doesn't have any obvious connection to Less Wrong, so I'm wondering where this overlap in readership came from.
[EDIT by E.Y.: The answer is that he's not popular here. The 2012 LW annual survey showed 2.5% (30 of 1195 responses) identified as 'reactionary' or 'Moldbuggian'. To the extent this is greater than population average, it seems sufficiently explained by Moldbug having commented on the early Overcoming Bias econblog before LW forked from it, bringing with some of his own pre-existing audience. I cannot remember running across anyone talking about Moldbug on LW, at all, besides this post, in the last year or so. Since this page has now risen to the first page of Google results for Mencius Moldbug due to LW's high pagerank, and on at least one occasion sloppy / agenda-promoting journalists such as Klint Finley have found it convenient to pretend to an alternate reality (where Moldbug is popular on LW and Hacker News due to speaking out for angry entitled Silicon Valley elites, or something), a correction in the post seems deserved. See also the Anti-Reactionary FAQ by Scott Alexander (aka Yvain, LW's second-highest-karma user). --EY]
The leap from "controlled experiments are not possible" to "one has to deduce from first principles" is huge and unsupported. The results of controlled experiments do not exhaust the available empirical evidence by a long shot. We have a lot of data about the effects of monetary policy from around the world. True, inferring causality from this data is not nearly as straightforward as inferring causality from a randomized controlled trial, but it's still a lot more reliable than deduction from first principles, I would think.
Think about how your argument sounds when applied to cosmological theories about the very early universe. We have a number of different theories that cannot be simultaneously right, and we cannot conduct controlled experiments. Would you endorse deduction from first principles in this instance as well?