PORTLAND – A Portland think tank released a report Friday that suggests Maine’s quality of education would deteriorate if voters approve a tax cap referendum.

The report by the Katahdin Institute research and education organization examined the effect that California’s Proposition 13 tax cap has had on that state’s school system since the cap was passed in 1978.

Mainers will vote Nov. 2 on whether to have 1 percent cap on property taxes, the same cap that is in place in California.

The 14-page report says California’s school system has fallen from being solidly funded and nationally recognized to being one of the poorest and most unequally funded in the nation.

The study says Maine has a similar education system as California had prior to its tax cap, and that residents should be concerned that schools here could decline if a tax cap passes.

The report was presented at a news conference attended by one of the report’s authors, a former director of California’s Board of Education, and a University of Southern Maine professor who formerly lived in California.

“California’s experience with Proposition 13 and its catastrophic effects to California’s education system should be enough to make any Maine voter think twice,” the report says. “The decline in California’s system confirms that…those who were warning of dramatic declines in 1978 were right on the mark – just as those concerned about the future of Maine’s education system are today.”

Tax cap supporters in Maine say there is disagreement over the condition of California’s school system, and that comparing Maine to California is not a valid parallel.

“Some people think California is an absolute disaster because of Proposition 13, and other people think it’s the greatest thing since sliced bread,” said Thomas McBrierty, a spokesman for Tax Cap Yes! and a former Maine economic development commissioner. “And that’s how people feel about the school system out there too.”

He said tax cap critics neglect to consider a referendum passed in June that forces the state to increase state aid for public schools to 55 percent of the total costs. The current level of state support for schools is about 42 percent.

McBrierty added that California has a large population with rapidly rising school enrollments, while Maine is a small state with a declining school-age population.