A new study documenting that Boston teachers earn nearly 30 percent more than their counterparts in cities including Buffalo, Cleveland, Denver, New Haven and Syracuse drew a predictably harsh response from the head of the Boston teachers' union. But the study's most important recommendation didn't make the headlines.

Education Resource Strategies, the Watertown, Mass.-based nonprofit that conducted the study, urged Boston to "prioritize or explore basing compensation increases primarily on [a teacher's] contribution rather than seniority." Judging from challenges to teacher-tenure laws that are making their way through the courts in several states, some people are less concerned with the fact that the average Boston teacher earns $88,564 in annual pay and $18,645 in benefits than with the fact that teacher compensation and job security appear to be largely unrelated to job performance.

In Minnesota last week, for example, four mothers filed a lawsuit arguing that the state's Teacher Tenure Act violates the right to a "thorough and efficient" education included in the state constitution. The law provides teachers with layoff protections after three years, requires a lengthy process for firing a teacher, and requires that those with the least seniority be the first to be laid off regardless of performance.

Lead plaintiff Tiffini Flynn Forslund says she decided to join the lawsuit after watching the state legislature fail to pass laws that prioritize effective teaching over experience. Her daughter's fifth-grade teacher was laid off because he had only been in the school district for a year. "I couldn't understand how such an excellent teacher could be laid off," she told the Minneapolis Star Tribune. "He outshined any teacher I had ever had or any of my kids had."

In just a week since the Minnesota lawsuit was filed, however, its prospects may already have dimmed. In the interim, a California appeals court reversed the controversial Vergara decision that threw out tenure-related teacher job protections. The North Carolina Supreme Court also struck down a law that phased out tenure protections for teachers, but that decision may be less applicable because the law in question would have stripped protections from teachers who had already earned them.

The lesson that state and local policymakers should take from these developments is that teacher quality is not only important to how well our children learn but also to voters. Regardless of how the courts rule, there is a growing consensus that it's time to change laws and stop negotiating collective-bargaining agreements that require teacher layoffs to be based solely on seniority.

The turmoil over teacher tenure also highlights the need for real teacher evaluations with consequences. Evaluations should focus on the rate of improvement in student achievement over time and they should impact promotions, compensation and job security.

And evaluations should also include, but not be limited to, rates of improvement on state standardized tests. The federal No Child Left Behind law went overboard with testing mandates, but the resulting backlash shouldn't obscure the work of renowned educational-standards expert E.D. Hirsch. He found that, although imperfect, standardized tests are still the best available predictor of economic success, civic engagement and even the likelihood that a person won't be incarcerated.

Recent events suggest that the parents of children in our public schools don't have a problem with teachers being well paid; they just want compensation -- as well as promotion and layoff decisions -- to be related to how well teachers actually perform in the classroom. That might not sit well with some, including teachers' unions, but it's a reality that they are going to need to deal with.