Jason Hackworth, a professor of urban geography at the University of Toronto, gave a guest lecture at the University of Michigan recently to pose a provocative question: "Why is there no Detroit in Canada?"

That is, in a nation where industrial decline was often as common as in the American heartland, why don't Canadian cities show the same level of blight and abandonment as we see in Detroit and Flint and in other post-industrial U.S. cities?

The question looms as more than academic interest. Our two nations and their economies share so much in common. Of special note in Detroit, there's the cross-border network of plants and suppliers that defines the modern auto industry.

If Canada somehow figured out how to avoid the devastation that factory shutdowns and job losses wreaked on U.S. cities like Detroit, it would be nice to know how they did it.

Hackworth's research showed it was not the loss of factory jobs alone.

"If you look at a lot of cities, they all have lost massive number of manufacturing jobs. Detroit's not that unusual in terms of numbers," he told me over coffee. "In fact it’s retained more than some the other cities."

Nor is the imbalance of taxes and services between city and suburbs in Detroit much different from what we see across dozens of metro areas. "It’s not a good explanation of why Detroit is so much more abandoned and depopulated than other cities," Hackworth said.

But the answer he came up with is frankly discouraging. It points to a big problem on both sides of the border.

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The more he looked, the more one big difference between Canada and the United States emerged: It came down to race. Put simply, U.S. cities tend to have large black and other non-white populations and Canadian cities do not.

American cities like Detroit gained black and other non-white residents in the early to mid 20th Century, sparking a white backlash that devastated those cities.

But Canada, which practiced more restrictive immigration and housing policies, blocked such an influx of non-white residents into their cities. So the relatively few non-white people in Canada could never create the same sort of economic impact as the larger numbers did in American cities.

"There's no chance they ever would be because there is no city in Canada that is a majority non-white city," Hackworth told me. "The biggest difference, it’s indelicate to put it this way, is that there’s no threat to white supremacy in Canada."

Hackworth may be the ideal scholar to examine this question. Born an American in Ohio, he earned his PhD in urban geography and eventually found his teaching post at the University of Toronto. Since then, he's attained dual U.S. and Canadian citizenship, which allows him to experience both sides of the border.

Canadians, he noted, often pride themselves on their nation not suffering the same race-based turmoil we often see in U.S. cities. But his adopted countrymen and women should hesitate to congratulate themselves, he said.

"Canadian society has invested a lot in what I think is a myth, that there’s not a race problem" in Canada, he said. "Like most national myth narratives, it’s almost entirely without foundation."

Over the decades, Canadian law and immigration policy, he said, have made sure black and other non-white populations remained small. Restrictive covenants in real estate sales, and an immigration policy that specifically gave preference to white people, kept the black population small.

Even today, the black population of Toronto remains under 10 percent, a far smaller proportion than in dozens of American cities.

Simply put, in Canada, white people never felt as threatened by a rising non-white population because there just weren't that many non-whites coming into cities like Windsor or Toronto. Hence, no Detroits in Canada.

I asked Hackworth if he had any suggestions for helping both nations with their racial divides.

"I think that two elements are pretty important — honesty and specificity," he said. "I think it is important to be honest about the role of racial animus in generating conditions like those visible in Detroit.

"Conversely I think it is important for Canadians to be honest about their own race problems rather than using the absence of places like Detroit as evidence that race problems don’t exist."

And, he added, it's important to drill down into the specific ways that racial tensions translated into vacancy and abandonment in places like Detroit.

How exactly did the racial divide translate into such devastation in American cities like Detroit? Hackworth lists several forces at work.

There were the legacy effects of redlining that deprived black neighborhoods of needed resources, something that arguably continues to this day. Then, too, numerous young black males were incarcerated for drug offenses that sometimes were not prosecuted in white suburbs, depriving black neighborhoods of needed workers and male influences.

And the white abandonment that hollowed out American cities like Detroit was not just an historic phenomenon of the 1950s, but something that continues today in many U.S. metro areas.

Granted, Hackworth's analysis can sound pretty discouraging to those who like to think we've moved into a post-racial era. But at least he's facing those problems with honesty.

"Changing those realities probably involves a mix of policy and change of sensibility," he said, "which unfortunately seems unlikely in this climate in either country."

Contact John Gallagher: 313-222-5173 or gallagher@freepress.com. Follow him on Twitter @jgallagherfreep.