The interests of teachers unions are too often at odds with those of students and taxpayers, and it’s time provincial governments and parents took a stronger stand, says a Halifax-based think tank.

A paper from the Atlantic Institute for Market Studies, generally regarded as right-leaning, argues for several changes in the collective agreements with teachers, including removing the right to strike, getting principals out of the unions, and adding merit as a factor in paying teachers.

The authors of Getting the Fox out of the Schoolhouse: How the Public Can Take Back Public Education also recommend that provinces fine-tune and expand standardized testing, and give parents more choice in where to send their children to school.

Charles Cirtwill, the institute’s acting president, said the paper points out how teachers unions have a disproportionate effect on the public education.

“They have more influence, more power, more say than parents, for sure, and in many cases, more influence and more say than departments of education or senior bureaucrats, or even elected officials,” Mr. Cirtwill said Thursday.

Mary Lou Donnelly, the president of the Nova Scotia Teachers Union, was out of the country and unavailable for comment. A communications staffer with the union said Ms. Donnelly was the only person who speaks for the union.

Education Department spokesman Peter McLaughlin said the department disagrees with the notion that the teachers union in Nova Scotia would have any kind of undue influence.

“Public education in the province is partnership. It always has been and always will be, and teachers are a valuable partner in that, just as school boards, parents and, in fact, any other Nova Scotian is,” Mr. McLaughlin said.

The authors — three Manitoba educators — say that teachers unions have an important role, but their policies and positions sometimes mean that the best interests of parents and students aren’t their first consideration.

For example, they say that during collective bargaining, school boards and provincial governments are interested in the best use of public resources and keeping costs down, while unions want to increase salaries and improve job security and working conditions.

Other problems the paper cites are basing teachers’ pay only on education and experience, rather than having a component to reward better teachers with higher salaries, and collective agreements that base layoffs and transfers on seniority, which makes it more difficult to get the best-suited teachers in the right situations.

The authors also take issue with some unions’ strict opposition to standardized testing of students. The paper argues that the right type of standardized testing is a good way to judge how students are doing, and indirectly, a good way to judge the effectiveness of schools and teachers.

Unions have argued that standardized tests don’t actually help students learn, and create unnecessary stress.

Mr. Cirtwill said the recommendations would have to be adjusted to the specific province, since some provinces have already tackled some of the issues.

He said Nova Scotia is doing reasonably well with its standardized testing regime, and it just needs a few tweaks. He said other provinces have changed teachers’ collective agreements in areas like moving principals out of bargaining units, and Nova Scotia could do the same.