I have a master’s degree in American history from New York University. It has been almost worthless and hasn’t done a thing for my career.

I started my master’s degree with Georgetown’s graduate program. Had I finished there I suspect that degree would also have been worthless.

Not worthless was the bachelor’s degree I got from Syracuse University’s Newhouse School of Journalism. The fact that I’m writing this column — and have been a journalist steadily for over 45 years – I guess proves that.

But even that degree probably only helped me get my first job.

I’m bringing up my personal stuff for a reason: A new study by TD Ameritrade shows that young millennials — described as people 22 to 28 years old — have mixed feelings about their college education.

“Our research found that for those young millennials who went to college, just 5 percent regret doing so,” says Dara Luber, senior retirement manager for TD Ameritrade. “However, when considering the value their degree had on getting their current job, roughly half said it wasn’t an important factor.”

Remember, these are people who graduated just a few years ago. And even in that short time span — when their college degree should have been most effective — the people who were surveyed said it wasn’t important.

And of course they didn’t regret going to college. It’s fun, although a very expensive way to enjoy oneself.

I’m not knocking a college education. Knowledge for knowledge’s sake about any subject — even history — is a good thing. But whether a college education is actually harmful to a person’s well-being has a lot to do with the cost.

If you really want knowledge at a discount, read a book.

There’s going to be a crisis in higher education one of these days. And it is a crisis that is going to affect the entire US economy.

The cost of a college education and the loans students have to take out are already a presidential campaign issue.

Democratic candidates Bernie Sanders and Elizabeth Warren have already brought up the (ridiculous) possibility of canceling all student debt — all $1.6 trillion of it.

But anyone who understands what is going on knows this is an empty promise. The US government, especially in its present state of indebtedness, can’t just pick up the tab for all those educations.

Somebody owns those $1.6 trillion in loans. And they’ll want to be paid to cancel them. And only the American government — aka, we the taxpayers — can do that. And we won’t.

Back when I erred in getting my master’s degree in history, the mistake wasn’t very costly. I didn’t have to take out huge loans that needed to be paid back over decades.

I didn’t have indebtedness from my college days that prevented me from buying a house or having kids.

That’s not the case today. Pick the wrong area of study — and by that I mean, one that doesn’t result in a high-enough-paying job — and students are condemning themselves to a much less affluent life.

And the student’s parents are doomed to seeing their kids achieve much less than they have and much less than their kids could have had.

Maybe that’s why TD Ameritrade’s survey also found that 20% of young millennials and Gen Z’s — ages 15 to 21 — “say they may opt out of a college experience,” says Luber.

A couple weeks ago I did a column about college costs that got a lot of attention.

Basically it asked a simple, but troubling question: Why are parents allowing their kids to pick overpriced schools that aren’t going to lead to jobs that earn enough?

Most of the people who wrote to me agreed that parents had abandoned their responsibility in this area.

Some said many parents aren’t equipped to make school decisions any more than their kids are, especially since colleges are so slick in their pitches.

And as long as parents and students don’t shop for value in colleges, the school administrators aren’t going to change.

They will continue to overbuild and overspend on things that aren’t necessary for an education that will pay dividends in the end.

This is a good time of year, with the fall semester about to begin, to talk about what students should study if they want to stay solvent.

LendKey Technologies, which has given out $1.02 billion worth of education loans, says that education, nursing, engineering and computer sciences have the lowest loan default rates.

Psychology, communications and liberal arts have the highest.

LendKey’s rule of thumb is that “you shouldn’t borrow more than the expected first year salary for a graduate of that degree.”

Here are some examples from LendKey: Agriculture majors make $40,000 the first year; journalism majors, $38,000; computer science $62,000; electric engineering $65,000 and elementary education majors earn $35,000.

“It’s not that some of these degrees are bad,” says Christian Widhalm, a senior vice president at Lendkey. “It’s just the fact that you shouldn’t borrow a lot of money to get these degrees. You shouldn’t put yourself behind the eight ball.”