According to a separate report by Customer Growth Partners, the fact that fewer than 50 percent of working-age adults have full-time jobs, sluggish growth in disposable income, and uncertainty about Puerto Rico and Greece are all dampening shoppers' appetites.
Read MoreCaution lights flashing for back-to-school sales
"Other than the tech side of it, I'm not sure I'm buying that excuse," said Craig Johnson, president of Customer Growth Partners.
NRF's Back-to-School Spending Survey, which polled 6,500 shoppers, found that total spending for school-age and college students is expected to reach $68 billion this year. That's down from $74.9 billion in 2014, with revenues from electronics projected to be particularly weak. Among K-12 parents, spending in this category is expected to drop 7 percent, whereas for college students, it's anticipated to fall 15 percent.
But electronics is not the only category in which parents plan to hold back. Spending on shoes is expected to drop about 6 percent among both groups, and apparel spending is also expected to decline across the board.
Read MoreRetail eyeing a cure for the summertime blues
Prosper Insights' Stacie Severs Nelson, whose firm conducts the NRF study, emphasized that the results do not take anything away from the "consistently more confident consumer" she's seen in 2015. Along those lines, the survey found that 76.4 percent of families with school-age children will alter their spending because of the economy. That's down from 81.1 percent in 2014, and is the lowest in the seven years the organization has asked that question.
"There's definitely an up-and-down flow with back-to-school spending," she said.