The tentative two-year contract agreement reached this week by the St. Paul School District and its unionized teachers underscores an issue faced by many metro-area school boards: How can budgets keep growing at a faster pace than revenue?

The St. Paul contract includes 2 percent pay hikes for teachers this school year and next. In total, the contract would add about $25 million in costs, including $21 million in pay and benefits for staff. The remaining $4 million would be used toward hiring 30 new counselors, nurses, psychologists and teachers for English language learners and it would be used on a plan to improve school climate over the next three years through pilot programs that emphasize relationship building over punishing students. Numerous violent incidents have occurred in St. Paul schools in recent years, prompting widespread concern about school safety.

The pay increases would come on top of the built-in hikes that come with longevity and education — so-called steps and lanes. Those automatic hikes can cost a district another 2 to 4 percent of current teacher payroll. Teachers earned an average of $70,000 in 2014-15, the highest teacher pay in the state and about $10,000 more than average pay in the metro area overall. St. Paul teachers are voting on the proposed contract this week, while the board is scheduled to approve it on March 22. The district's total annual budget is $697 million.

Minnesota teachers and school districts have settled 198 of 356 contracts statewide, with average salary increases of 2 percent in the first year and 2 percent in the second, according to Education Minnesota, the state's teachers union. And like St. Paul, the state's second-largest district, some Minnesota districts will have to make budget cuts in other areas despite modest increases in state funding over the last two sessions.

During a Star Tribune Editorial Board session this week, several metro-area superintendents expressed concern about the rising costs of teacher contracts.

They're right to be concerned, and as this page has previously argued, district leaders and the Legislature should examine whether steps-and-lanes schedules should be changed. While seniority and experience matter, school districts would benefit if the automatic hikes covered fewer years. And many experts agree that acquiring more academic credentials does not necessarily improve teaching.

To be sure, there are other ways to help relieve school budget pressures. More federal and state aid for special education, for example, could free up millions of dollars for Minnesota schools. But there is a lot of competition for those funds, and political support is never a sure thing.

In the meantime, salary and benefit costs are the largest share of school budgets. And because of that, school districts need the flexibility to negotiate wages without being locked into excessive automatic increases.