Tribeca rolled out its big premiere of the documentary version of “Freakonomics” last night, which economist and star Steven Levitt hadn’t even seen yet. I asked him what he thought of it afterward and he said he thought it was pretty good but “I wouldn’t pay to see it.”

That tells you something about the movie’s commercial prospects, which are highly limited. It has five parts (one of them dispersed throughout the picture directed by “King of Kong” director Seth Gordon). The first, directed by Morgan Spurlock, trades heavily on ethnic and class stereotypes in an effort to make some cheap, and tasteless, jokes about baby naming. (Stereotypically black names such as Roshonda, according to studies, cost a kid job opportunities.) The second episode, directed by the leftist Alex Gibney, was even worse — an exploration of a Sumo wrestling cheating scandal in Japan that bizarrely tried to bring in the 2008 Wall Street crisis and Bernie Madoff to make some sort of angry point about how the system is corrupt and stacked against us truth-tellers. The Eugene Jarecki-helmed third part, about the most notorious chapter of “Freakonomics,” had an appropriately mournful air as it explored the unintended side benefit of Roe V. Wade — legalizing abortion decreased the crime rate 15 years later because fewer unwanted kids were being born. The fourth part, by Rachel Grady and Heidi Ewing, was by far the best. It used an entirely appropriate blend of humor and seriousness to tell the story of a University of Chicago economists’ study that involved visiting a high school and seeing whether 9th graders who were failing could be bribed to succeed–get your grades up to C’s, win 50 bucks. The economists concluded at the end that the 9th graders were simply too old, their studying habits too engrained, for bribery to make much difference. This was the one segment that treated its subjects as individual characters, and by the end of it you will feel you know the two 9th graders that are its stars.

Overall, economist-author Steven Levitt is very much the star — he’s a handsome, charismatic guy who could host his own talk show (assuming there was such a thing as a smart talk show, and I don’t think there is) and his stories about bribing — er, using incentives to encourage — his own family were a treat. The movie has been picked up by Magnolia.