Rare occurrence

Reading the new JEL that came in the mail yesterday and I happened upon a first (for me, at least). DiNardo ("Interesting Questions in Freakonomics"; a misleading title since he argues forcefully that there are less of these than one might think) rocks a double-footnote! That's right, kids, he footnotes footnote # 29 with footnote #30, which is an all-star move if you ask me.

This would be nothing more than a neat, unusual occurrence if the section (and the footnotes) weren't so good. DiNardo uses Freakonomics, and for those who've read it, it's preoccupation with correlation vs. causation, as a jumping-off point to discuss randomized controlled trials and the assumptions needed to assume that RCTs can give good estimates of a treatment effect: "...in an RCT, the answer should be insensitive to the addition of additional controls."

This is a recommended piece of work.