In recent years, slow home construction, declining new-car sales and the poor performance of brick-and-mortar retailers have all been blamed on the "unique tastes and preferences" of those born between 1981 and 1997. That means millennials have been accused of killing everything from canned tuna to the suburbs.

Actually, though, millennial habits are not so different from that of previous generations, "once the effects of age, income, and a wide range of demographic characteristics are taken into account," according to a new paper by the Federal Reserve.

Younger people are spending less because they have less money to spend, the Fed concludes.

"Millennials are less well off than members of earlier generations when they were young, with lower earnings, fewer assets, and less wealth," write authors Christopher Kurz, Geng Li and Daniel J. Vine.

"For family income," they write, controlling for age and work status, "Generation X and baby boomer households have a family income that is 11 percent and 14 percent higher, respectively, than that of demographically comparable millennial households."

That jibes with recent research showing that the median millennial only has $2,430 in savings and that a growing percentage of millennials have absolutely nothing saved. In fact, that generation is still largely relying on Mom and Dad for help: Most American adults between the ages 21 to 37 receive financial assistance from their parents or guardians, according to a report from Country Financial.

That doesn't necessarily indicate they're bad at putting money away — it could mean they just have less to work with. In 2016, millennials had more in their retirement savings accounts than other generations at comparable ages, the Fed says, though that may reflect the replacement of pensions with defined-contribution accounts.