Millennials with student debt burdens are not buying as many cars or houses as previous generations. But what about other types of consumer spending? Can Millennials afford to break the bank this Black Friday or on future Black Fridays when so much of their income is sucked away by student loan debt? 

"We don't spend money in silos," Mark Huelsman, Senior Policy Analyst at Demos, told attn:. "If student loan debt is slowing spending in expensive markets like housing and automobiles, it stands to reason that less expensive consumer spending -- like buying Black Friday items -- will be affected as well."

Coming off the Great Recession, consumer spending has struggled to return to robust pre-2008 levels. Wages have remained stagnant while fewer Americans are using credit cards. Without access to plastic or increasing salaries, there is less available money lying around to be spent on consumer goods. Student debtors, moreover, have the added problem of monthly loan payments, which also reduce disposable income.

Huelsman explained that it's hard to isolate exactly where Millennials with student loans will reduce spending. We can't know, for example, whether a student debtor would have purchased an Xbox One this year if not for those pesky student loan payments. But we do know that student loan debt creates financial uncertainty, which affects spending habits across the board.

Venture capitalist and NBA owner Mark Cuban is worried about student loan payments crowding out consumer spending.

"That's the same money that, when you graduated, you used to move out of the house or you went out and spent money that improved the economy and helped companies grow," he said at a recent conference. 

Cuban proposes that the government place a cap on the amount of loans a student can borrow. He believes this would force colleges to control costs more.

No one has researched whether Millennials will have different overall retail spending habits as a result of student loan debt. It's fair to guess, though, that if car salesmen and realtors are not seeing Milliennials come through the door, then eventually Amazon, Best Buy, and Target might be affected by similar changes in customer behavior. With consumer spending making up 70% of the U.S. economy, we'll eventually find out if Millienials are aren't spending their fair share to keep the economy afloat.

In the short-term, what can we make of a successful Black Friday?  Will it mean that consumer spending, as a whole, is coming back? Possibly. But it could also be a sign of weak consumer spending with Americans waiting around for deep discounts because they don't have the money to pay normal prices.

"The vast majority of shoppers this weekend will be elbowing one another not because they are looking for great deals on the brands they love," wrote Jonathan Salam Baskin, a marketing expert. "But because they can’t afford to buy the stuff otherwise.