A new report from the Center for American Progress chronicles the biggest worries currently facing the country's biggest retailers. Unemployment is up there. Stagnant or shrinking incomes, rising costs, and weak consumer confidence are too. But the most prevalent thing scaring everyone from Walmart to Amazon, McDonald's, Whole Foods, and even Apple is that people still aren't buying enough stuff.

Nearly 90 percent of the America's 100 largest retailers cited being scared of low consumer spending in their most recent 10-k form, according to CAP's analysis.

By just about every measure, Americans still aren't opening up their wallets the way, say, retailers, would hope. Part of that has to do with the fact that wages, especially among the middle class, have been flat or falling, a fact that two-thirds of the big retailers also say they're concerned about. "The culprit is obvious: low wage and income growth for the middle class," the report says. But part of that also has to do with the fact that even when people are making more money, they aren't turning around and spending it—recent rises in income haven't been met with commensurate increases in spending. A recent poll confirms that: people, it seems, aren't spending as much as they could, largely because they still aren't making as much as they'd like.

For that reason, and the reality that things don't appear like they're changing anytime soon, retailers are already fretting about what looks to be a disappointing holiday season.