As Citizenship and Immigration Canada conducts ongoing public consultations on the mix and number of immigrants the country should take in, a pioneering study has offered a powerful argument for prioritizing “skill-assessed economic immigrants,” whose earnings levels, the study has found, far exceed those of other kinds of immigrants.

Motivated in part by the rapid rise in the overall level of immigration, which has continued despite the economic downturn, as well as changes in the type of immigrants admitted, a pair of Queen’s University economists are weighing on several contentious aspects of Canadian immigration policy just as that policy is being reviewed.

Their working paper on the differences in earnings across different categories of immigrants in Canada, which was released this month through the Canadian Labour Market and Skills Researcher Network, found that economic immigrants, whose admission is determined by a points system that measures education and experience, had median earnings that were as much as 56 per cent higher than other classes of immigrants.

A recession, meanwhile, was shown to have “very marked and long-lasting scarring effects” on the earning power of immigrants of all stripes.

Commonsense though the findings may seem, rarely have they been so definitive. In an effort to gauge how well immigrants are integrating into the Canadian labour market, Michael Abbott and Charles Beach tapped CIC for a decade’s worth of annual earning data for all immigrants that arrived as landed immigrants in 1982, 1988 and 1994.

“It’s not a sample. It consists of the totality of all immigrants who have arrived in … those respective years,” Beach told The Huffington Post. “That makes it really quite large and, if you wish, more reliable than any other study that’s out there.”

By comparing the annual earnings of four different classes of immigrants -- economic immigrants, those who accompanied them, family class immigrants, and refugees -- the researchers were able to quantify just how much skills matter.

What they found was that the 10-year median earnings levels of economic migrants significantly exceeded those of the other classes -- between 30 and 37 per cent higher for men, and between 39 and 56 per cent higher for women.

The study found that refugees and family class immigrants -- those who came to join family already here -- had the lowest earnings levels. The real earning levels of refugees declined over the each successive cohort, suggesting that it got more difficult over time for this group to make ends meet.

But regardless of their skill level, immigrants felt the sting of recession. In 1990-1991, there was a decline in the median real earnings of male immigrants in all four admission categories in both the 1982 and 1988 cohorts. Meanwhile, those who arrived in 1994 experienced relatively low initial annual earnings, suggesting that the downturn continued to take a toll on immigrants, even after it was officially over.

A similar trend was observed in the aftermath of the recession in the early 1980s for those who arrived in 1982.

“That was actually a bit surprising to us,” says Beach of the effect of recession on immigrant earnings. “Perhaps it shouldn’t be, because there’s an of old rule of thumb in labour economics that says, ‘Last in, first out.’ If a recession comes along, and people get laid off on the whole, it’s the most recently hired, people with less tenure or seniority in the firm. And immigrants in general are people who have recently arrived.”

It’s a finding he says should prompt policymakers to consider reducing the number of immigrants admitted during tough economic times.

“In this recent recession and period of slow growth, that’s not what’s happened. The tap not only has been kept on, it’s been increased,” he says, adding that there has also been a growing number of newcomers admitted as foreign temporary workers and provincial nominees.

Total immigration to Canada has risen from 84,000 in 1985 to more than 280,000 in 2010, the highest number in more than half a century.

Immigration numbers vary from year to year, but they have been on an upward trend for decades, and last year’s 281,000 arrivals was the highest number since 1957, when Canada took in 282,000 immigrants.

Family class immigrants currently make up 26 per cent of those admitted; immigrants chosen for their economic potential, meanwhile, make up about 30 per cent.

Beach says the outcomes of skill-assessed economic immigrants is a testament to their relative success -- and the fact that the proportion of those admitted under that category should not be reduced.

“If we want to get immigrants to do well in Canada, that category is the one [that] does consistently better than the others,” he says.

But changing the mix of immigrants Canada takes in could have a political cost. Earlier this year, Immigration Minister Jason Kenney came under fire after reports showed that CIC was planning to reduce the number of family reunification visas by five per cent in 2012.

On Monday, Kenney’s ministry launched an online online questionnaire -- the department’s latest attempt to get public input on the appropriate mix of immigrants.

“The online consultation provides an important opportunity to gather input from stakeholders and the public on key questions facing CIC,” says Minister Jason Kenney. “This is also a chance to highlight some of the considerations and difficult choices involved in managing a global immigration system.”