In the six decades after 1950, Minneapolis seemed resigned to a kind of hollow success. Glassy towers filled the skyline, the arts flourished and the lakeside neighborhoods retained their leafy charm. Yet the city as a whole kept shrinking and getting visibly poorer.

By 1990, Minneapolis had lost a third of its population, then grew only modestly over the next 20 years. By 2009, average household income had fallen to 30 percent below the metro median.

By contrast, the suburbs boomed. Over the same 60-year span, the metro population tripled to 3.4 million and, by 2010, the metro economy had overtaken Detroit's as the Midwest's second-largest. So, in some sense, the 1950-2010 period was a tale of two cities.

Then something clicked for Minneapolis. Starting in 2011, the city began to grow at a faster clip, adding nearly as many people in two years as it had in the previous 20. New apartment buildings rose by the dozens in the University District, along the Midtown Greenway and even in the downtown core. On the North Loop's crumbling sidewalks, next to the tower cranes and construction crews, baby carriages began to appear.

Demographers were wary of announcing a full-blown trend. But it was possible to imagine that Minneapolis was finally experiencing something that had started 20 years earlier in similar cities.

After 1990, Denver, Seattle and Portland each added huge chunks of population — between 140,000 to 166,000 residents each — mainly by attracting a larger share of those who otherwise would have settled in the suburbs. Some were empty-nesters enticed by the convenience of restaurants and cultural attractions. But many were young singles and families, people with stronger ties to their mobile devices than to their cars, people searching for energetic urban lifestyles without having to move to ultraexpensive New York or San Francisco.

Whether Minneapolis can follow that lead is an open question. It can't wave a magic wand and expect the market to respond by supplying thousands of new residents every year. But the city's political leaders, after decades of glossing over population losses, are suddenly touting population gain as key to the city's future.

"By 2025, we want 450,000 people to live in Minneapolis — about 65,000 more than today," Mayor R.T. Rybak said in his final state of the city speech in April. "We want to do that without disrupting the character of our strong single-family-home neighborhoods, and without putting a single additional car on the street."

Rybak's optimism isn't out of bounds. The city has led the metro area in new housing units by a wide margin for the last six years. Even though it's growing at only half the current rate of Denver and Seattle, Minneapolis will easily reach the mayor's goal if the trend continues — and the city could conceivably climb back to its historic high of 522,000 by 2040.

For Minneapolis, population growth — especially middle-class growth — is less a matter of civic pride than economic necessity. Without more taxpayers, the city will soon be unable to afford the services that residents expect. Or, to put it another way, adding middle-class population is the best way — perhaps the only way — to keep property taxes at a barely tolerable level.

In that sense, growth is a survival issue. Older cities, like older homes, face huge repair and maintenance costs. They carry the burdens of housing, educating and handling the social problems of most of their region's impoverished people. They play host to many thousands of visitors who use the city but don't fully contribute. And many are stuck with cumbersome bureaucracies and pension liabilities.

Still, a few of those cities have made themselves so appealing that people are willing to pay a reasonable premium to live in them. Indeed, an economy that demands efficiency and an environment that coaxes people onto smaller footprints have played into the strengths of cities like Denver, Seattle and Portland. In turn, each has sought to maximize population growth by encouraging density in commercial districts, retrofitting industrial areas for new housing and expanding transit to ease traffic congestion.

Minneapolis can take similar advantage if it does several things:

• Accept density. Density doesn't mean apartment towers in the midst of single-family neighborhoods. And, if transit is expanded, it doesn't necessarily mean traffic nightmares. What it does mean is more intense development along major streets and at major intersections (for instance, Dinkytown or Nicollet-Lake). It means converting underused industrial land to housing. And it means infilling downtown parking lots with housing and other development. The Downtown Council's 2025 plan counted 120 such sites.

Convincing large employers to invest in the city would help, too. Amazon's decision to forsake a suburban campus and relocate up to 30,000 workers to downtown Seattle will reshape that already booming city. Minneapolis pins similar hopes on a smaller but significant Wells Fargo plan near the new Vikings stadium.

Accepting density also requires a change of mind-set. Growth should be infused into all city policies. Example: an elaborate plan for parks along the Mississippi riverfront north of downtown somehow failed to include housing. That was a mistake. More parks aren't much good without more people. As University of Minnesota urban geographer John S. Adams says about urban policy: "Everything is related to everything else."

Other density boosts might include: a lower tax formula for condos (they use fewer services per unit); experiments with form-based zoning codes, a streamlined development review process, and incentives for taller buildings and sturdier construction.

Density is not for everyone, and it's not right for every corner of the city. But there's more than enough room for Minneapolis to grow. "Whoever you are, whatever you want, more people is the answer," said David Frank, hired by the city in 2011 to promote transit-oriented development. "Lower property taxes? Yes. Safer streets? Yes. More and better restaurants and local businesses? Yes. More support for the arts? Yes. A better chance to solve poverty? Yes."

• Expand transit. Density doesn't work without it. There should be zones in Minneapolis where walking, biking and transit-riding are clear choices over driving. Here's the upshot: Minneapolis cannot and will not grow without a sustained build-out of the transit system. That means a half-cent sales tax increase to support the Southwest and Bottineau light-rail lines, expanded bus rapid transit, and regular bus service that's so frequent that schedules aren't needed. That's the kind of system that rival cities have. It also means modern streetcars of the kind that drew $3.5 billion in private real estate development (including 10,000 new housing units) to Portland between 2001 and 2009. (More on transit in Part 4 of this series.)

• Solve the school problem. A huge deterrent to middle-class population growth is distrust of the city's public schools — or, more accurately, a perception that impoverished, low-performing children diminish the chances for all children to learn. Finding ways to involve parents, improve the learning atmosphere and boost student performance has been elusive. Closing the city's notorious race/class achievement gap is essential if Minneapolis is to prosper. Building a middle class "of color" should be the city's top priority. That starts with better school performance and a Herculean effort on job training. (More on disparities in Part 3 of the series.)

• Control crime and the perception of crime. Violent crime has steadily declined since the "Murderapolis" days of the 1990s, and that has greatly improved the city's growth potential. While crime rates cannot be fully explained by police and court strategies, it's likely that proactive policing — anticipating who commits crimes and where they occur — played a big role. The problem comes when proactive policing turns into racial profiling and the harassment of innocent people. A delicate balance must be struck. Just as difficult is the task of fighting the "perception" of crime: policing streets dominated by loiterers and panhandlers who aren't committing crimes but who nonetheless diminish the confidence in public spaces that successful cities require.

• Keep property taxes in check. It's a kind of Catch 22. Minneapolis can't grow if property taxes continue to rise, but neither can it grow if it fails to invest in its quality of life. The Legislature has made matters worse by cutting state aid to the city by $455 million over the past decade. Growth is the only solution, even though density is a difficult concept for many residents to embrace. City Council President Barbara Johnson rightly suggests a generational split. Older residents grew up in a city of declining density. (Minneapolis went from nearly 9,700 people per square mile in 1950 to 6,800 in 1990.) But younger people's appetite for compact living is causing a political shift in density's favor, she said, plus "the realization that we can't keep raising property taxes."

• Beautify public spaces. Cities hoping to attract population growth must have appealing public spaces. Minneapolis' park system is impressive. But the city's downtown area, despite recent improvements, badly needs an extensive streetscape and greening makeover. To that end, the Downtown Improvement District should be expanded; a stricter surface parking lot ordinance should be adopted and enforced; freeway entrance points should be landscaped; and Nicollet Mall should be recast. It's not helpful that many of the prime areas for growth — most of them on downtown's periphery — have the shabbiest public spaces.

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For the first time in six decades, Minneapolis is showing the potential and the appetite for growth. It must take advantage of the moment.

"Other cities have already made the choice to grow," said Frank, the city's transit/development specialist. "They are pulling away from us. We can see their taillights getting smaller in the distance."

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