The ‘Idol’ threat is not an idle threat

Fox’s “American Idol” has been a hit for so long that viewers just take for granted its locomotive-like power. But those freight-train Nielsens aren’t just sweeping away rival networks’ piddling comedies; erstwhile hits are getting blown off the tracks too. Just consider the results Wednesday night, when “Idol” pretty much demolished ABC’s “Lost” and NBC’s “Law & Order.”

Wednesday’s results-show “Idol,” which dashed the hearts of pre-teen girls and dotty grandmas everywhere by finally booting contestant Kevin “Chicken Little” Covais, delivered 27.3 million total viewers, 11.3 rating/26 share in the adults ages 18 to 49 demographic, according to early figures from Nielsen Media Research.

“Idol” lasted just from 9 to 9:30 p.m., but that was more than enough to gut-punch the other networks. Head to head against the singing contest, “Lost” subsided to its lowest rating in that demographic so far this season (6.6 rating/15 share; 16 million total viewers), a long way from the invincible hit it seemed at season’s outset.

Then there was NBC, which saw its risky new Wednesday lineup implode. “Law & Order’s” move one hour earlier, to 9 p.m., proved a catastrophic mistake. The program drew its worst rating in the demographic since at least 1991 (2.6 rating/6 share; 9 million total viewers), an outcome virtually guaranteed to send its outspoken creator, Dick Wolf, into new paroxysms of grouchiness and blame-slinging. He’ll have a point this time, because NBC damaged “L&O;” for the sake of premiering “Heist,” a bling-bling caper that delivered an abysmal third place in the 10 p.m. slot (3.0 rating/8 share in demo; 8.7 million total), opposite “CSI: NY” on CBS and ABC’s new procedural “Evidence.”

Fox got a predictably so-so result from the 9:30 premiere of a new game, “Unan1mous,” in which a group of people angle to win a $1.5-million jackpot. But even so, “Idol” was strong enough to allow Fox to easily win the night -- and, once again, give rival executives pause. CBS has found some success counter-programming Fox with shows like “NCIS.” Can’t anyone else learn to play the game?

Dialogue cooked up for ‘Park’s’ Chef

“South Park” began its 10th season Wednesday night with “The Return of Chef,” which basically serves as the producers’ response to last week’s thoroughly weird events surrounding cast member Isaac Hayes, who resigned from the show apparently in response to its ridicule of Scientology.

Thumbnail notes ... (and a hearty spoiler alert to all those who TiVo’ed) ....

* Logline: Chef returns to South Park but seems “trippy.” The kids discover he’s been brainwashed by the Super Adventure Club, a secret society that advocates child molestation. So they take him to a strip club to try to snap him out of it. It works, sort of.

* The Verdict: Funny, although once you get past the central joke, maybe not clever enough to rate among “South Park’s” very best. The language and sexual situations are pretty raw even by the show’s liberal standards. This is one Kevin Martin could use to exploit the FCC-should-regulate-cable-indecency issue.

Co-creator Trey Parker, credited with the script and direction, reportedly constructed Chef’s dialogue from vocal bits Hayes had already recorded before leaving the show. Given how “Return” ends, plus the fact that Hayes has voiced the character since 1997, we’re betting Chef will be around in some form for quite a while. Hayes’ spokesman, per MTV.com: “He was under contract when he recorded the vocals, so they can do anything they want with them.”

Students follow the ‘Mad Money’

Many investors have long suspected that Jim Cramer, host of CNBC’s popular “Mad Money,” can be hazardous to your nest egg. But now three students from Northwestern’s business school have analyzed how Cramer’s stock picks actually perform.

Answer: Not so good.

As anyone with a passing interest in finance knows, the premise of “Mad Money” is simple. A Steadicam tracks the bald, bearded Cramer, eyes gleaming, pacing around the studio like a backwoods revivalist, shouting hosannas to his favorite stock of the moment (which, more often than not, he says is guaranteed to go up, up, up) and pausing only to smack oversize buttons on a control panel that cue various silly sound effects, such as the Hallelujah chorus or a trumpet fanfare.

Entertaining? Sure, and it’s undeniably helped CNBC’s once-struggling evening lineup. Trouble is, “Mad Money” is, according to many critics on the Street and beyond, a bad bet for the 400,000 or so viewers who regularly tune in. Now students at Northwestern’s Kellogg School of Management -- Joey Engelberg, Caroline Sasseville and Jared Williams -- have documented ways in which they say that Cramer’s picks can be problematic.

Essentially, the researchers argue in their March 15 report that those who rush to act on Cramer’s picks at the start of the next trading day pump up the volume and the price of the share in question, which after a few days will inevitably fall like raindrops in Hana. The only folks who make money are those trading sophisticates who “short” Cramer’s picks -- i.e., make bets that the stock price will fall.

As Engelberg summarizes: “Cramer pushes up prices about 5% overnight for the smallest stocks and about 2% overnight for our entire sample. However, the entire run-up in price (including the run-up due to information leakage) completely reverses within several trading days (i.e. stocks, on average, fall to their original prices).”

Asked for comment on the report, a CNBC spokesman complained of “huge holes and serious inaccuracies” and then followed up with a statement, which said in part that the report “is a ‘working paper’ and a posting from three students on a chat site.”

The statement added: “Jim does not choose stocks in a vacuum -- he, like other professional investors, reacts to various news in the marketplace, such as a good quarter, a mention in other media, an analyst upgrade or a settlement of a lawsuit.” (For the full statement, log on to latimes.com/channelisland).

We wanted to ask the biz school students for their reaction to CNBC’s criticism, but the students were not available for comment. One staffer said many students and faculty are out this week for spring break.

Channel Island is a blog about the television industry. For the latest posting, go to latimes.com/channelisland. Contact reporter Scott Collins at channelisland@latimes.com