The Harper government has been so stingy with details about its efforts to stimulate Canada's stuttering economy, it's impossible to tell if they've had any impact, the parliamentary budget watchdog says.

In a report released late Friday, Kevin Page's parliamentary budget office says quarterly report cards issued by the Canadian government fall far short of the transparency and detail provided in the United States.

That has made it difficult to track where the $12 billion in stimulus funding has gone and whether it's had any effect on economic growth or job creation.

The government claims its stimulus funding, announced in last January's budget, will increase economic growth by 1.9 per cent and create 220,000 jobs.

But Page's office says that is impossible to prove, given the skimpy details the government has provided and the inherent uncertainty involved in trying to assess what the economy would have been like had there been no stimulus measures.

"This means that at the current time it remains unclear as to whether the domestic fiscal stimulus enacted thus far has been a major causal factor in the recent stabilization of some indicators of economic activity in Canada," the report concludes.

"Similarly, it cannot be conclusively ruled out that the stimulus has mattered to date (or will matter in the future) in the aggregate or for specific sectors, such as financial markets."

Page's office says the government will have to adopt the more transparent approach used in the U.S. if it wants a more conclusive analysis.

Among other things, it says the government will have to start making a distinction between money that's been committed and money that's actually been spent, as is done in the U.S.

And it will have to be more consistent in its presentation of quarterly results. The watchdog says it has been almost impossible to track some of the funds because the government keeps reclassifying or changing the names of stimulus programs from one report card to the next.

The government has been relatively thorough in disclosing all relevant details about small stimulus measures, such as support for shipbuilding and enhanced work-sharing flexibility.

But Page's office says there's been "a lack of disclosure regarding some of the larger and higher risk aspects of the stimulus package, in particular infrastructure spending."

Liberal infrastructure critic Gerard Kennedy calculated recently that only 12 per cent of infrastructure stimulus funds are actually flowing. He's uncovered dozens of projects that the government has announced with great fanfare but on which no work has actually been done.

Transport Minister John Baird, who is responsible for infrastructure programs, has scoffed at opposition demands for greater transparency in reporting where the stimulus cash is going.

He's suggested he'd rather spend money on real infrastructure projects than a fancy website such as that sponsored by the U.S. government.

A spokesman for Baird insisted the government is transparent, posting projects on its website the moment they're announced publicly.

"Our focus is getting projects approved and creating jobs," said Chris Day.

"We will continue to report on our progress to Parliament."