Elementary school applications are due in a month, which raises questions—as it does every year—for parents of kids who are technically old enough to start kindergarten in the fall, but who will be younger than most of their classmates.

Two years ago, I was one of those parents. My son's birthday falls at the end of the year, which means he'd always been one of the youngest at daycare and preschool. If I'd been planning to put him in private school (or if we lived almost anywhere outside New York City) he'd have been scheduled to enter kindergarten in 2012, after his 5th birthday. Since city schools determine grade assignments by calendar year, he was slotted to start in the fall of 2011, while he was still 4. I decided back in preschool that at some point early on, I'd finagle the start of a school year so he wouldn't move forward with the age cohort he was born into. So, this year he finds himself in kindergarten for the second time.

According to the National Center for Education Statistics, I'm far from alone: Somewhere between 9 and 14 percent of kids across the country either start kindergarten late or repeat their kindergarten year.

The science on whether that extra year offers a long-term advantage is ambiguous. Some studies have found that kids who are older than their classmates do better academically for many years; others have found that the positive effects wear off, and even that delayed-entry kids do worse in their adult lives.

The politics are equally fuzzy: Low-income kids and children of color are far less likely to start kindergarten late, but more likely to be held back by their schools. Middle-class parents are much more likely to choose the delay for themselves—hence the term 'redshirting,' frequently applied to wealthy parents who are presumed to regard education as a competitive sport, setting up their kids to win at any cost. (Or, more to the point, at the expense of the age-appropriate kids they go to school with—and of course, an extra year's tuition at private preschool.) From a policy perspective, starting school younger has the potential to diminish the learning gap that separates rich and poor kids the first day they walk into the classroom.

This year, the DOE made it harder to put off kindergarten, mandating that kids who skip kindergarten must go straight to 1st grade, the following year. But there's more than one way to slow down an educational trajectory. For us, doing kindergarten twice has been a solid, though imperfect solution. While his future personality, academic and otherwise, has yet to be demonstrated, so far my son has proven himself to be a silly, kind, social kid who would much rather build block castles and make up jokes than recite phonetic combinations. His first year of kindergarten was good: I watched him morph from a baby to a big, confident kid in what seemed like a matter of weeks. He made friends and counted pigeons and started to read.

But it also seemed unlikely that he was ready to move on. Whether they think it's a good or bad thing, most people in the world of New York City education agree that 1st grade has become much more infused with academic expectation than it used to be. There are lists of sight words and skill-differentiated reading groups. There is a lot of sitting at tables and desks.

Ambiguous science notwithstanding, repeating kindergarten has given my son an extra year to play and explore, to synthesize his own weird, idiosyncratic take on the world without worrying about what he's supposed to already know. It seems to me that all that will come soon enough.