If Ontario’s high school graduation rate hit 90 per cent, that would save the province more than $16 million a year in spending on health care, social assistance and the justice system, says a report released Wednesday.

But if the rate drops to 82.6 per cent — the current rate is 86.3 per cent — that would add $18 million in costs, says an analysis by the Conference Board of Canada that was commissioned by the Ontario Secondary School Teachers’ Federation.

“Our findings suggest that for each $1 increase in public education spending, $1.30 is generated in economic impacts for the province,” states the report. “Apart from the direct economic impacts to the province, there are also indirect social (or public) benefits that can stem from public education spending.

“There are positive externalities that flow from having a better-education and better-informed population.”

The report comes as the province is phasing out 3,500 teaching positions over the next four years, and decreasing per-pupil funding.

While education funding is up overall, that is largely due to an increase in enrolment, the Ford government’s child-care rebate and the first instalment of an “attrition fund” set up to prevent any layoffs as the teaching positions are lost.

The province is boosting class sizes by an average of one student in Grades 4 to 8, and from an average of 22 students to 28 in high school. However, because those are averages, secondary classes will grow much larger.

The Halton public board has warned of classes with up to 46 students, and all boards are cancelling courses or sections to deal with the loss of educators.

“We have always taken the position that public education is an investment in Ontario’s future, and this research provides solid evidence that this is true,” OSSTF president Harvey Bischof said in a written statement. “In light of this evidence, we will be urging the Ford government to look closely at this Conference Board of Canada report, and to seriously reconsider the cuts it has planned for education in Ontario.”

The Toronto District School Board alone is looking at almost $70 million in cutbacks, with $42 million of that due to provincial funding changes.

NDP Education critic Marit Stiles said the Ford government’s cuts “could hurt high school graduation rates, while also costing Ontario more money.”

“This report echoes what the NDP has been saying,” Stiles said. “The Ford government’s education cuts will rip away supports students need to thrive academically, like smaller classes, one-on-one attention from teachers, and elective course offerings that give students a chance to discover their own gifts and talents.”