Here is the new version of the paper, for $5. Here are older versions of the paper. Here is a summary of the five questions. Of these five, I worry most about getting uninformed traders to participate in a game with zero-sum (at best, assuming no trading costs) pecuniary returns. I doubt if idea futures will be the sexiest form of gambling for most people. Insofar as traders look for fun, only the celebrity-obsessed and current events-obsessed will find idea futures more attractive than Las Vegas or Baden-Baden. (That is why contracts on politicians and Michael Jackson have been so popular.) If you are simply looking to earn money for the longer run, Wall Street, with its positive expected rates of return, offers better odds. That being said, as the fixed costs of market creation fall, a relatively small number of traders may suffice to keep most of the important idea futures going.