DENVER, Colorado (AP) -- Every year, Greg Ahrnsbrak decides whether to keep his job as a public school teacher or look for a career that would pay him more money."I don't believe that all teachers, after year 13, hang up their books and say 'I'm not going to put forth any effort,"' says Ahrnsbrak, who has taught in Denver Public Schools for more than a decade. "Realistically, though, I don't care what profession it is, you still have bills to pay, families to support."On Tuesday, voters will decide whether to approve a $25 million annual property tax hike that would dramatically overhaul how city teachers are paid. Among other things, the plan would link teacher salaries to student achievement, rather than years of service and education level.Teachers' unions have generally balked at pay-for-performance plans instead of guaranteed raises and salary scales. The proposal here, however, was put together by the Denver teachers' union and school district administrators after a four-year pilot program -- and experts say educators and policy-makers around the nation are watching the vote with interest.Tricia Coulter, director of the Teaching Quality and Leadership Institute at the Education Commission of the States, said more and more attention is being paid to how teachers are paid. She said the Denver plan offers examples in both developing and implementing a program."The timing is perfect. Everyone is looking at these," Coulter said. "It's definitely being watched very closely."Supporters say the Professional Compensation System, or ProComp, would help attract and retain good teachers and improve student performance by rewarding educators for meeting achievement goals. Opponents say it would add nothing but bureaucracy and subjectivity to how teachers are paid and do little to actually help the district's 73,000 students.Marsha Burger, who teaches English at Abraham Lincoln High School, worries ProComp will encourage teachers to think only of themselves and their paychecks. She also believes a clause linking evaluations to raises will lead to confrontations."Your evaluation is based on your principal, who may or may not like you," said Burger, who has taught in Denver public schools for almost three decades. "It's a violation of union ethics that we've all believed in, which is that workers all deserve to be treated equally and fairly."Denver's 4,000 public school teachers are currently eligible for 13 salary increases, based on years of service and professional development, such as additional degrees or certification.Under ProComp, teachers who now earn a base beginning salary of $33,301 a year could double their salaries over a 25-year career. Raises would be built into four categories: knowledge and skills, the evaluation, market incentives and student growth. For example, additional money could be earned for meeting student achievement objectives or for exceeding expectations on statewide tests."This is one of those things that really is in everyone's self-interest," DPS Superintendent Michael Bennet said. "It's in people's self-interest to raise student achievement. It's in people's self-interest to get great professional development. It's in everybody's interest to inspire teachers to work in places that are hard to staff, that have unique challenges."If the property tax hike is approved, ProComp would begin in January. Current teachers do not have to participate, though new teachers must use the new scale.The plan was backed by 59 percent of union teachers in March 2004 and some of the concepts are familiar to the rank-and-file: Every Denver public school teacher since the 2003-04 school year has been required to set achievement goals for students.Valeri Kershaw, a seventh- and eighth-grade literacy teacher at Bruce Randolph Middle School, said the achievement goals have helped. Teachers can work together across subjects, principals have a better idea of what teachers need and students have a clearer idea of what is expected of them."Instead of experience being the motivator for more pay, it's nice to have a system where skill and expertise in a certain area allows for a pay increase," she said.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.