I’m starting to believe Chris Kennedy is serious when he says he would bring “radical change” to Illinois’ property tax system if he became governor.

He’s certainly passionate about the subject.

Kennedy even performed his own mini-study comparing sales prices of individual properties to the values set by the Cook County assessor’s office.

Kennedy’s results closely mirrored the findings of a more extensive investigation published recently by the Chicago Tribune, which concluded the property-tax assessment system is fundamentally flawed, to the detriment of those owning the least expensive homes.

Kennedy had shown me his study before the Tribune reported its findings, and while his work wasn’t thorough enough for me to draw definite conclusions, it was certainly eye-opening.

       OPINION

Unlike the Tribune, Kennedy also looked at the assessments on major downtown commercial properties, which, to my mind, does a better job of making his case that the “system is rigged.”

Kennedy’s study shows it’s not uncommon for major Loop skyscrapers to sell for more than double the market value pegged by the assessor’s office.

“As bad as the residential inaccuracies are, the commercial inaccuracies are greater,” Kennedy told me. “The magnitude of the problem is much larger and the effect on everyone else much worse. These are big dollars.

“This is such a clear indictment of the lack of accuracy, of the lack of rule of law in the system. There’s no choice but to call for change.”

This is also where a small coterie of politically connected law firms specializing in property-tax appeal work make their living, not on those residential properties. These include law firms led by House Speaker Michael J. Madigan and Chicago City Council Finance Chairman Edward M. Burke.

Without calling out Madigan and Burke by name, Kennedy has said state law should be changed to prevent elected officials from acting as property-tax appeals lawyers.

He also wants public officials barred from taking political party leadership posts — a shot at both Madigan, the state Democratic chairman, and Cook County Assessor Joseph Berrios, who chairs the county Democratic Party.

Both changes would be pretty radical by Illinois standards.

Also regarded as radical, though I don’t see why, is Kennedy’s contention that actual sales prices should be used as the best indicator of a property’s value, not the convoluted machinations the assessor’s office and property-tax lawyers rely on to justify lower assessments.

“Anyone who argues with that is trying to muddle your thinking or confuse you,” Kennedy said. “If I buy a house for $500,000, I should expect it to be assessed at $500,000.

“They want a black box,” he said. “They want something that you don’t understand. They want hocus-pocus, the razzle-dazzle, because it allows the elected officials who act as property-tax appeals lawyers to make money off the game. That’s all this is about.”

I have a slightly different view. I believe the hocus-pocus is designed to protect the big-money interests, and, over the years, the politicians figured out how to exploit that for their own benefit.

Either way, it leaves us with a broken system.

As a businessman who has worked in real estate, previously running one of Chicago’s most valuable buildings in the Merchandise Mart and now developing new properties, Kennedy has firsthand knowledge of how the system works.

That experience might make him an imperfect candidate, seeing as how he has used the system to his own advantage to lower his taxes.

At the Merchandise Mart, then owned by his family, Kennedy used former Cook County Assessor Tom Tully as his real estate lawyer and later hired his firm to appeal the taxes on his home. He even used Madigan’s firm on an office building his group bought at 33 N. Dearborn — his explanation for both being that, in Chicago, the property-tax lawyer essentially “comes with the building.”

More revelations about his holdings in the course of the campaign might hurt the messenger. They shouldn’t detract from the message.