AUGUSTA — Despite a dramatic rise in per-pupil spending on education across the country, and in Maine, SAT scores have stayed stagnant, according to a report released Tuesday by the Cato Institute, a conservative think tank based in Washington, D.C.

The report says that in Maine, overall spending has increased by 180 percent since 1972, while SAT scores have declined by about four percent during that time.

“The goal is to get the biggest bang for our buck that we can,” said Andrew Coulson, who authored the report. “If we really care about education, it isn’t enough to spend more on it.”

“Surely if we’ve done anything right in tripling spending, surely we should see some benefit to that,” he said. “My hope is that people will invest money more wisely.”

The report tracks how much each state spent on public, K-12 education every year since 1972 and compares it with students’ results on the SAT, a test that is used by many colleges as an admissions exam. The amount spent by states is adjusted for inflation, Coulson said.

Maine is one of only two states that requires students to take the SAT, so the state’s average score is typically lower than other states, where only students who choose to take the test because they are applying to college are measured. However, Coulson said his data adjusts for dramatic changes in patterns in the data, such as participation rates and student demographics.

Lois Kilby-Chesley, president of the Maine Education Association, said SAT scores do not give a complete picture of what’s happening in classrooms.

“We have to look at our children as being more than the result of test scores,” she said. “There are so many more pieces. What do we really want from our children when they graduate? Do we really want children who can just take tests?”

“It was never meant to be an achievement test,” she said of the SAT, which is an aptitude test.

Though the Maine Department of Education declined to comment on the report from the Cato Institute, director of communications Samantha Warren defended the state’s use of the SAT as its achievement test in an email.

“Obviously the state has had the SAT as its high school state and federal accountability measurement for nearly a decade, not only because it aligns with our state learning standards and math and critical reading and because we believe it is a valid measure of student aptitude in those content areas, but also because requiring the participation of all students in that raises expectations and aspirations and increases readiness for college or other post-secondary opportunities.”

Starting next year, Maine will no longer use the SAT to measure student achievement, but will switch to a new test that is aligned with the state’s updated learning standards.

Coulson said he used the SAT because of the scope of the data it provided.

“There is no other data series that reaches back to the early 1970s for every state in the country,” he said.

David Silvernail, director of the center for educational policy, applied research and evaluation at the University of Southern Maine, said a closer look at Maine would reveal a higher correlation between spending and student performance.

“I know national studies find very little relationship between spending and performance,” he said, explaining that studies like this one take into account spending on all costs associated with running schools, including those that have nothing to do with instruction, such as transportation and facilities.

“If you get inside the state, there is a correlation between spending and performance. It’s a low correlation,” he added.

Silvernail said that per-pupil spending has gone up in Maine in part because of a steadily declining student population.

“If you’re in a rural community, you may lose 20 students, but all those students may not be third-graders so you can reduce one staff member,” he said. “Your [per-pupil] expenditure goes up even though your actual personnel has not gone up.”

Lois-Chesley pointed out that the state of Maine pays teachers less than most other states.

According to the National Education Association, Maine ranked 43rd in the country in starting salaries offered to teachers in 2012-2013. The starting salary for a Maine teacher was $31,835, while the national average was $36,141, according to the NEA.

Maine ranked 35th in the country in average salaries teachers made in 2013, according to data from the National Center for Education Statistics, reported by the Washington Post.

“I think Maine has done a really good job of being accountable for where the money is used,” Lois-Chesley said.