Worried? Americans should be.

Still, acknowledging the problem is perhaps the easiest step. Much more difficult is the question of what to do about it. Not surprisingly, young, heavily indebted grads are calling for forgiveness in full or in part of their student loan burdens. Petitions on advocacy website Change.org include calls for federal student loan interest rates to be capped at 3 percent or eliminated altogether. (Indeed, President Obama is currently among those urging Congress not to allow the interest rate on federally subsidized Stafford loans, which are aimed at low — and middle-class borrowers, to double to 6.8 percent on July 1, matching the rate for unsubsidized loans.)

And yet the trouble with those initiatives, or with forgiving student loan debt in whole or part, is threefold. For starters, the straight mathematics: the losses from any such debt reduction scheme will have to be borne by someone, most likely taxpayers, at a time when government finances are already stretched.

Second is the issue of “moral hazard,” that is, rewarding and implicitly encouraging imprudent behavior rather than punishing it. (Of course, it is easier for the public at large to demand that over-leveraged banks be punished for imprudence than 24-year-olds trying to further their education.)

And third is the question of how to keep future graduates from accumulating a mountain of student loan debt just as large, if not larger, than the one just leveled.

It is this third issue which perhaps is most pressing — and most vexing —and which also offers the most opportunity for innovation. Levying an “education tax,” making college free and assigning students to institutions based on a lottery system? Abolishing “college” altogether for more specialized trade institutions instead, while at the same time requiring a “gap year” of liberal arts prior to entry? Offering high-school grads the choice between student loans or business loans to fund new ventures? These all seem ridiculous, but then so too is our current state of affairs.