Despite a value decline of 18 percent since the peak of the real estate market in 2005, housing in Greater Boston is less affordable than ever, and that significantly threatens the region’s economic future.

That was the conclusion of the 2009 Greater Boston Housing Report Card, prepared by the Kitty and Michael Dukakis Center for Urban and Regional Policy at Northeastern University, along with The Warren Group, publisher of Banker & Tradesman, and the Citizens Housing and Planning Association.

This year’s presentation is titled, “Positioning Boston in a Post-Crisis World,” and is set to be unveiled Wednesday morning at The Boston Foundation.

“With housing prices falling, one naturally assumes that while that’s bad in general for people with homes, it’s good in terms of affordable housing,” said Barry Bluestone, director of the Dukakis Center. “In fact, affordability has sharply declined through the recession.”

Home values have decreased 18 percent in the Greater Boston area since 2005, according to data from The Warren Group. But home values have decreased nationally by 30 percent, according to the Case/Shiller Index, which tracks house pricing nationally.

“We are now more expensive, relatively,” said Bluestone. “The actual price is lower, but the relative price is higher.”

Meanwhile, rents have risen 11 percent since 2005. Bluestone said the demand for rentals have increased as foreclosures have skyrocketed, and as home values steeply declined, traditional homebuyers were hesitant to buy before the bottom on the market.

“They had a tendency to sit on the sidelines and stay in rental housing, when normally that would have turned over for somebody else,” he said.

With housing starts – both single family and multifamily – down 77 percent in 2009 from its peak in 2005, Bluestone said, rents will continue to rise in the near future.

That threatens the region’s hopes for prosperity in the 21st century, according to Boston Foundation President Paul Grogan. The foundation has commissioned the Housing Report Card each year since 2003.

“We’re still not in the situation where we are creating housing at all price points that combats the disadvantage in the region, and that’s a serious problem in the medium and long term,” Grogan said.

Boston needs to eliminate the “disadvantage” of expensive housing, because it’s currently fighting America’s “Third Civil War,” according to Bluestone. The first Civil War is well known. Bluestone considers the Second Civil War to have been fought again between the North and South, but this time over where the country’s industrial and manufacturing might would be centered, and the South won.

In Bluestone’s third Civil War, the combatants are major cities and metro regions. The prize: America’s young, skilled and mobile workforce.

With Baby Boomers retiring, cities will have to compete for the new backbone of the workforce in a time where technology and transportation has made it ever more mobile.

“[Cities] will need them to retain their employment base, and their tax base … and therefore metro areas are going to have to do everything they can to make themselves attractive to young, working families,” Bluestone said. “We continue to find more evidence that for the high-flyer metro areas, the ones with the highest housing prices, there is growing and powerful evidence that those metro areas are pricing themselves out of the market for young, working families.”

And by 2006, according to Bluestone, Greater Boston lost 6 percent of its population it had in 2000. People are leaving in search of a cheaper place to live.

Grogan said Boston’s major resource was intelligence: it’s the university and hospital capital of the country. But without enough affordable housing to both retain the talent that comes through the city, and to give local families and their children the opportunity to become that talent, Boston could find itself left behind in the 21st century economy.

“It really goes to the whole talent question: Will this region have the talent, the manpower to have a stable economy going forward?” Grogan said. “We absolutely need to have public policy that will allow people to stay, and let people to choose to stay.”