Since 2006, Pennsylvanians have been able to vote on proposed school-tax increases that exceed a state-set education inflation rate.

That might surprise those who have watched their taxes go up well beyond that rate year after year but who have never been asked to vote on them.

That's because the law also allows tax hikes for certain spending categories without voter approval.

Now, with the support of the Corbett administration, Republicans in the state House and Senate have introduced bills that would remove those exceptions and require all proposed tax increases above the education inflation rate to be placed on the ballot.

Rep. Seth Grove (R., York), who introduced the House bill, said he was determined to close the "Grand Canyon-size loophole."

Since 2007, when the law was expanded to include all districts except Philadelphia, more than 2,000 school budgets have been enacted statewide, but only 11 proposed school-tax increases or tax hikes for specific projects have been put up for a vote. All but one were defeated.

There has been just one referendum on a budget tax increase in the Philadelphia area's 63 districts. In four of the last five years, at least a third of school-tax increases in the area have exceeded the education inflation rate.

Some districts - Cheltenham, Haverford, Lower Merion, and Lower Moreland - have never passed a budget with an increase below the inflation rate, using the spending exceptions to bypass referendums. Only 11 area districts stayed below the rate every year.

Others - Bristol Borough, Centennial, Octorara, and Upper Dublin among them - used exceptions that allowed them to raise taxes during the last five years that averaged more than twice the 3 percent rate of education inflation.

Ending the exceptions would lead to a dramatic change in the way school budgets are decided. Supporters see the legislation as a way to control spending by forcing school boards to justify tax increases to voters.

Many school board members fear that passage would choke off money for education and throw budgets into chaos.

Having to make big changes in a budget if it failed in a referendum "would wreak total havoc on our process," Cheltenham school board President Tina Viletto said.

The vote would take place on primary day, usually in May, when turnout is usually low. If a tax increase was rejected and reduced to the inflation rate, the district would have to scramble to make cuts by June 30, when school budgets must be adopted. The inflation rate for next year was set at 1.4 percent.

In Cheltenham, tax increases have been used to maintain arts, theater, music, and sports offerings as well as programs, such as full-day kindergarten, that are the "lifeblood of the district," Viletto said. Though the district plans no tax increase for next year, "many of our costs are fixed" in the long run, she said, and "we would have to look at everything" if a lid were put on increases.

With only about 20 percent of residents having children in the schools, Viletto said, "you really are risking a tremendous amount in the quality of educational programs. Look at New Jersey: Referendums there don't necessarily pass, even if the budgets there are worthy. And you are dependent on the turnout at the polls. It would really pit the parents of the past against the parents of the present."

In Montgomery County's Spring-Ford School District, the board is considering raising taxes about 3 percent next year - more than double the inflation index - even after deciding to cut some staff positions, contract out others, and postpone textbook purchases, board President Joseph Ciresi said.

The district is allowed to raise its taxes above the inflation rate because of exceptions for special education and pension expenses and to bolster slipping local tax revenue.

Spring-Ford tax increases have generally stayed below the inflation rate in recent years, but if it had to do that this year, Ciresi said, "we would have to furlough a significant number of additional teachers and cut programs. It would be devastating."

As for getting voter approval, he said, "educating the community enough to get them to understand exactly what the stakes are and what we can and can't control would be very difficult. You would have a lot of automatic no votes. It's human nature - none of us wants to pay more."

The law that established school-tax referendums, known as Act 1, allows districts to raise taxes above the inflation rate without a vote for any one of 10 purposes. They include debt payments, employee retirement contributions, and special education expenses above the rate of inflation; school construction; and increases to make up for declines in local and state revenue.

The bills that would amend Act 1 have the backing of the state Education Department. "This bill simply requires that those who bear the responsibility of financially supporting their local schools have a direct voice in determining the level of support they can afford," the department has said.

The Senate bill has been passed by the Finance Committee; a vote by the House Finance Committee is scheduled this week. The legislation is one of several companion education bills that many expect to be considered when a state budget is completed.

Even without referendums, Act 1 has helped keep taxes lower, said Jay Himes, executive director of the Pennsylvania Association of School Business Officials. On average, he said, only about a quarter of districts have exceeded the inflation rate.

"The index has been institutionalized as the barometer" that school boards use to gauge how much they should raise taxes, Himes said.

An analysis of Philadelphia-area tax increases before and after Act 1 tends to confirm that view. In the two years before Act 1 passed in 2006, the average school-tax increase exceeded 6 percent. Since the law took effect, it has been 4.5 percent. More than half of Philadelphia-area districts raised taxes by less after Act 1 passed.

Keith Knauss, a school board member in Chester County's Unionville-Chadds Ford district, said he favored removing the exceptions. Before he was on the board, he helped defeat two referendum proposals asking for approval to renovate the high school.

"It's a good check and balance on school boards," Knauss said. "I don't believe the typical administration has kept a very good limit on either the number of employees or what they are paid. This is a good way to set a limit."

He added: "I trust the public. I don't have a problem with going out to ask for increases more often if they are needed."

The board plans to keep taxes below the inflation rate this year, he said.

In Chester County's Great Valley School District, which has stayed under the index most years, the tax increase is expected to exceed the inflation rate next year.

Resident Audrey Van Loan, a frequent critic of school board spending, said she endorsed removing the exceptions from Act 1.

"If they are over inflation, residents should vote on it," she said. "Gov. Corbett is doing what has to be done. He doesn't hate children - there is no money. They have to face the facts. If it takes a law to do that, so be it."

Contact staff writer Dan Hardy at 215-854-2612 or dhardy@phillynews.com.