Some other people in economics had discovered special cases of the theorem of Rabin before hand as well. I haven't gone through Gelman's piece here. How general is it?
Sounds plausible. But in fact, it's 100% false. The phenomenon was first described in an obscure book chapter by a Swedish philosopher named Sven Hansson. Hansson's theorem is described in a footnote on page 1 of Rabin's 2000 econometrica paper. Hansson is listed in the references of Rabin and Thaler (2001) but not cited anywhere in the text. Odd omission.
http://w3.psychology.su.se/staff/osn/
Hansson proved an equivalent version of Rabin (2000) as did Gelman (1998).
Rabin claims that Samuelson's (1963) effect is a "weaker case" than Rabin's calibration theorem. This is false. Samuelson's effect is much different from Rabin's effect and much simpler.