CASPER, Wyo. — Sixteen-year-old Kaytie Christopherson was getting ready to do her homework on a Friday when she got a call that made a big improvement in her life: She had won a brand-new pickup truck for near-perfect school attendance.

And not just any truck, but a $28,000 Chevrolet Colorado crew cab, with an MP3 player.

"I take it everywhere. To work, school. I don't know, anything I do, I have it out with me," the high school junior said. "I pay attention to where I park it, though."

Public schools commonly reward excellent attendance with movie tickets, gas vouchers and iPods. But some diligent students like Kaytie are now hitting the ultimate teenage jackpot for going to school: They have won cars or trucks.

School districts in Hartford, Conn.; Pueblo, Colo.; South Lake Tahoe, Calif.; and Wickenburg and Yuma, Ariz., are also giving away vehicles this school year.

In most cases the car or truck is donated by a local dealership, and the prizes typically are awarded through drawings open only to students with good attendance.

So does bribing students with the chance of winning a car actually get them to think twice about staying home from school? Some educators think so, and say their giveaways have boosted attendance. But the evidence is not clear-cut.

Kaytie — who has a 4.0 average at Natrona County High — won her truck last spring, in the school system's first such drawing. But she said that was not what motivated her to keep up her attendance; she just didn't want to fall behind.

District attendance officer Gary Somerville said he hopes to raise attendance and also reduce the district's 29 percent dropout rate, which he blames in part on Wyoming's booming gas-and-oil industry.

"These kids can go out and earn $15, $16, $17 an hour swinging a hammer. It's kind of hard to keep them in school past their 16th birthday," he said.

Hartford has been holding a drawing — for either a car or $10,000 — for six years.

"I can't tell you that it's increased attendance," district spokesman Terry D'Italia said. "But what it has done over the years is just kept a focus on it and kept it at the top of kids' minds."

Jack Stafford, associate principal at South Tahoe High School, said attendance increased slightly last year, the first year the school system gave away a car, and is up slightly so far this year. He said changing times call for such incentives.

"My mom had the three-B rule: There'd better be blood, bone or barf, or I was going to school," Stafford said. But "that's not the case now."

Only 98 of Natrona County's 3,200 sophomores, juniors and seniors were eligible for last year's drawing. They were allowed only one excused absence, and no unexcused ones.

Districts have a lot to gain and little to lose by holding car drawings. In Wyoming, even a one-student increase in average daily enrollment means another $12,000 in state funding for the year.