QUESTION: Tell me what you think of the (public, real-money) &#8220-prediction markets&#8221- (a.k.a. betting markets) without citing the names of either Robin Hanson or Justin Wolfers. Thanks. Are they useful, really? If not, then why are econ bloggers in love with them?

FELIX SALMON (#):

I used to be a bigger fan of them, before I discovered their enormous transaction costs:
http://www.felixsalmon.com/004529.html
If and when somebody makes an easy legal and cheap prediction market, I think it will be very useful indeed. For the time being, they&#8217-re interesting and fun.