Editor's note: LZ Granderson writes a weekly column for CNN.com. A senior writer and columnist for ESPN The Magazine and ESPN.com, he has contributed to ESPN's "Sports Center," "Outside the Lines" and "First Take." He is a 2010 nominee and the 2009 winner of the Gay and Lesbian Alliance Against Defamation award for online journalism and a 2010 and 2008 honoree of the National Lesbian and Gay Journalists Association for column writing. (This weekend, watch "Don't Fail Me:" Education in America examines the crisis in America's public education system and the risk to the nation's financial future if students can't excel in math and science. Sunday, May 15, 8 EST.)

Grand Rapids, Michigan (CNN) -- As a nation, either our kids are getting dumber or everyone else's are getting smarter. American 15-year-olds ranked 14th in reading, 17th in science and 25th in math in a study of students in 34 nations and nonnational regions.

The Program for International Student Assessment study, coordinated every three years by the Organization for Economic Cooperation and Development, definitively shows U.S. students are no longer ready to compete against the world's brightest.

Which brings me to this: Why are we still giving them the summer off?

As it stands, only eight of the Organization for Economic Cooperation and Development countries that took part in the study in 2009 have a lower high school graduation rate than we do. It's so bad in some schools, educators have a nickname for them: dropout factories.

That's a national crisis with a potential for significant economic impact. The organization estimates that by boosting our scores for reading, math and science by 25 points over the next 20 years, the United States would gain $41 trillion over the lifetime of the generation born in 2010. As cash-strapped as we are, can we really afford to leave that kind of money on the table? Instead of year-round school as curiosity, I think it's time it becomes a government-enforced standard.

Remember recently when the nation got all in a tizzy after the International Monetary Fund reported China would pass us as the world's largest economy in 2016? Well, considering Shanghai ranked No. 1 in the education report, that shouldn't really surprise anyone.

To make matters worse, our kids have no idea just how far behind they really are.

When the results of the test were released in the winter, Arne Duncan, U.S. Department of Education secretary, pointed out that despite not being in the top of any of the subjects tested, "U.S. students express more self-confidence in their academic skills than students in virtually all OECD nations. This stunning finding may be explained because students here are being commended for work that would not be acceptable in high-performing education systems."

It's as if the United States were cast in one of those cliché Hollywood movies as the 29-year-old dumb and balding jock who still wears his high school varsity jacket.

Cutting into summer vacation won't solve all our education problems -- most research points toward the quality of the teacher as the biggest influencer -- but more class time could help. At 180 days, we have one of the shortest school years of the countries tested. South Korea, for example, has 220 school days, and a No. 2 ranking in math. Finland is first in math and science at 190 days.

Then there's this: Harris Cooper, a summer-learning expert at Duke University, pored over a century's worth of data and found that each summer, our kids lose about a month of progress in math and that low-income students lose as much as three months' worth of reading comprehension.

Again, that's each summer.

More than a month of teaching time at the beginning of the school year is spent re-teaching the stuff our kids forgot over the break. This may be one of the reasons why the report suggests Finnish 15-year-olds are one to two years ahead of our kids in math and science.

Now I hear the cry from some who say "Let our kids be kids," but what does that mean today? The reason for summer vacations in the first place was that little Johnny was needed in the fields to help the family during growing season. Today more people live in cities than they do in rural areas, and that farming structure has been obsolete for some time. If our kids aren't working on the farm all summer long, what are they doing?

Watching TV?

Playing video games?

Getting into trouble?

Heck, a lot of our kids' summers and holiday breaks are already structured around Amateur Athletic Union practices and tournaments. Why is it so wrong to suggest structuring the summer around more education, especially when the amount students receive is no longer enough to keep them competitive on the world stage?

In July 2008, then-Sen. Obama suggested American children should learn a second language. That was met with a great deal of criticism, as if being bilingual and more educated was somehow un-American.

You want to know what's un-American?

Not being innovative. Refusing to think outside the box.

We used to be a nation of entrepreneurs and trailblazers, but now we're just dogmatic consumers. We want problems to be fixed but we don't want the solution to be an inconvenience. So we look for silver bullets, which in our culture usually means tossing more money at things. But guess what? We spend on average about $30,000 more per student than the other Organization for Economic Cooperation and Development countries, yet the best we can do is middle of the road.

Since when did chanting "We're No. 25!" become acceptable?

Today, if you want to keep your child in a learning environment during the summer, you most likely have to pony up hundreds, if not thousands, of dollars to enroll them in a program or two. Families who can't afford to do that depend on scholarships or programs funded by government grants or corporations. If you grew up poor like me, and no extra income was available for transportation to those programs, you simply stayed home and watched TV every day for hours.

In retrospect, I would have been better served being in school.

I would imagine teachers wouldn't be thrilled to give up their long vacation. And the athletic apparel companies that enjoy the income Amateur Athletic Union summer leagues generate wouldn't like it much either. Nor would the colleges and universities that rake in extra cash brought in by hosting summer programs.

But the biggest obstacle to re-evaluating summer vacations is probably our love of the familiar. As humans we are naturally averse to change and the end of summer vacations would greatly alter the way we've done things for more than 100 years.

But what terrible thing would happen if we made the entire year part of the education process, with mini-breaks sprinkled throughout? Year-round schooling would not be repealing the child labor laws of 1938 and it won't force kids to lose their childhood. But it would give our young more of a fighting chance. The world is getting smaller, the world is getting smarter and if you look around you'll see when it comes to education, we're no longer basking in the glow of superiority.

We're wallowing in mediocrity. And our kids don't even know it.

The opinions expressed in this commentary are solely those of LZ Granderson.