TORONTO - At $53 million, Ontario's four-year public probe into child abuse in Cornwall cost more than the province's last three public inquiries combined.

And even Premier Dalton McGuinty is asking why.

"That's a good question: does it really have to cost this much?" McGuinty said Wednesday.

"There's an accountability to taxpayers, just as there's going to be an accountability to the folks in Cornwall to get this behind them."

Knowing the question would be asked, the Liberal government made legislative changes that took effect Tuesday -- the day the Cornwall report was released -- to give it "greater authority" to limit the scope of inquiries and keep costs down, he said.

Future commissions won't have to be formal, full-scale proceedings, which can become time-consuming and costly. They will also be required to rely, where appropriate, on sources such as representative witnesses, agreed statements of facts and existing records and reports, officials said.

Inquiries have increasingly become more complex and costly in recent years, and it's difficult to pinpoint exactly why, said Attorney General Chris Bentley.

They're more legalistic, with more attention paid to the process, he said. The changes to the Public Inquiries Act, which passed during the fall legislative session, will pave the way for more focused public inquiries and provide additional support to help them complete their work within a reasonable amount of time.

The Goudge inquiry on child deaths that slammed the work of once-eminent pathologist Dr. Charles Smith is a good example of the kind of tightly focused, efficient probe that Ontario may see in the future, Bentley said.

The inquiry saved time by tabling records as accepted fact, rather than requiring testimony, for example.

But the independence of the inquiry will still be preserved under the new rules, Bentley said.

"It's a very delicate balance," he said. "If you lose the independence, then you lose the reason the inquiry was called in the first place."

Cornwall inquiry Commissioner G. Normand Glaude released a 1,600-plus page report Tuesday that left the sensational allegations that fuelled the inquiry unresolved.

The inquiry's more than $50-million price tag included $21 million in legal fees, $3.5 million in counselling costs and $308,054 in Crown expenditures.

By comparison, the Goudge inquiry cost about $10.1 million and released its findings just 18 months after it was established in April 2007.

The Ipperwash inquiry into the fatal shooting of aboriginal protester Dudley George, which released its findings in 2007 after two years of hearings, cost about $29.5 million. The inquiry into the Walkerton tainted-water tragedy, which released its findings in 2002, cost about $9.7 million.

Inquiries may be expensive, but they have real value that can't be measured in dollars and cents, said Bryan Evans, a politics professor at Toronto's Ryerson University.

"Absolutely it's worth it," Evans said.

"In terms of providing clarity, identifying injustice, identifying failed procedures and institutions -- you know, typically they're a good investment."

McGuinty said he's glad the Cornwall inquiry has wrapped up its work.

"You can't help but have detected that there was something amiss in Cornwall when I visited there in recent years," he said.

"I hope that this has brought some closure to it and enables people to move on and the community as well."