Obligatory http://xkcd.com/552/ http://xkcd.com/552/ I read an article in The Economist some time ago about speculative trading in oil markets. People were ra

Obligatory http://xkcd.com/552/ http://xkcd.com/552/ I read an article in The Economist some time ago about speculative trading in oil markets. People were raising a ruckus about how it raised the costs of heating for the poor. Turned out that the evidence showing causation was extremely flimsy, and many other global trends were much better explanations. I think burden of proof is on the article to make the case for causation, and I didn't see it (although I skimmed the second half).