Across the U.S., nearly every state uses a child’s fifth birthday to determine when they can enter the public school system as kindergartners. If your child’s birthday falls just after the cut-off, those few extra days can mean an entire extra year at home or paying for preschool.
Sending most five-year-olds off to school is a relatively new phenomenon. State funding for universal kindergarten picked up in the 1970s, an extension of broader anti-poverty and education initiatives under Lyndon B. Johnson’s Great Society legislation of the 1960s and concurrent with changing family roles that saw more mothers entering the workforce. But the shift to full-day kindergarten was not immediate, and program design often looked more like daycare than formal schooling. Gen X and elder millennial parents have vague memories of playing kickball and scribbling with crayons from that first year of formal schooling; today’s kindergartners take standardized tests.
So what happens if your child isn’t ready for today’s design?
Richard Reeves, founder and president of the American Institute for Boys and Men, has written extensively about academic redshirting—where a child waits an additional year to start kindergarten despite eligibility—going as far as to call for all boys to start school a year later than their female peers.
“The reason little boys wear almost all of the red shirts is not mysterious,” Reeves wrote in The Atlantic back in 2022. “[T]he fact that boys mature later than girls is one known to every parent, and certainly to every teacher.”
The decision to redshirt—which feels huge to any exhausted parent of a young child—is made with incomplete information. Do you register your son according to the rules? Or do you place a bet that waiting will keep him out of trouble, make him a star football player, or improve his SAT score down the road?
Like most big decisions, either choice comes with tradeoffs. Being relatively older may, in fact, lead to a range of benefits across the school years. But the research isn’t clear on how long these benefits last. Diane Whitmore Schanzenbach and Stephanie Howard Larson explored academic redshirting back in 2017, and determined the effects fade over time. And peer effects matter: being around older, more advanced students can push kids to level up.
Against the backdrop of decision-making with imperfect information, Tímea Laura Molnár of Central European University set out to understand how academic redshirting affects student achievement and mental health by gender. She designed a causal study using academic and medical data for over 300,000 Hungarian children, plus mental health survey data for about 10,000 children, spanning from 2006 to 2017.
In Hungary, children born in September through December were subject to a school-readiness evaluation if the parent wanted to delay their start, a requirement that did not apply to those born after the first of the new year. Children born in January through May could wait for the following school year or start school without a readiness evaluation, and those with summer birthdays (those on the older end of the cohort) started on time based on a June 1 birthday cutoff. By reviewing outcomes for similar children born on either side of January 1, Molnár identified the Local Average Treatment Effect (LATE) and extracted valuable insights about whether the perceived benefits of redshirting play out in real situations among otherwise similar children.
It turns out that the perceived benefits are real—but only for boys, and especially for a subset of boys.
Academic gains started early for boys who waited to start school, scoring 0.3 standard deviations higher on sixth grade math tests and 0.29 higher in reading compared to their on-time peers. From there, the long-term impact takes shape. Because Hungarian children sort between academic and vocational tracks after primary school, early academic gains pave the way for redshirted boys to be 31 percent more likely to end up on an academic track. By tenth grade, the redshirted boys scored 0.20 to 0.25 standard deviations higher than on-time peers in math and reading and were 26 percent more likely to be aiming for a post-secondary degree. They went on to be 15 percent more likely to graduate high school. The redshirted boys were also less anxious, more confident, and bullied less.
Molnár’s sample design helps us understand why redshirting is sometimes a good choice. The required formal school-readiness evaluation for children born between September and December served as a deterrent for parents who were on the fence about whether their child needed extra time before entering formal schooling. Thus, the boys whose redshirting rested on that evaluation requirement were more likely to already show signs of being developmentally less ready to begin formal schooling, whereas children born just past January 1 only needed a childcare provider to sign off. By comparing children born on either side of the January 1 cutoff, Molnár can isolate the causal effect of redshirting separate from other factors that may influence a parent’s choice to delay their child’s school start.
The results did not hold for girls: redshirting had no measurable effect on their outcomes. This null effect may be part of why redshirting closed the boy-girl gap in high school completion by up to 60 percent and the boy-girl gap in academic track participation by 80 percent.
Molnár separately looked at how starting school just before or after the firm June 1 cutoff affected outcomes and found that while redshirting did not make a measurable difference for girls, being older did.
So what should parents make of this information?
The Molnár study shows that the boys who benefited from delaying their school start showed signs of being less ready than their similar age peers, though not always with a formal diagnosis. Parents, pediatricians, and preschool teachers can consider factors like delayed start to speaking, chronic illness, and attention issues, all of which point toward serious consideration of redshirting.
However, parents in the U.S. can’t look to Hungary for clear answers about when their child should start formal schooling. Molnár was looking at children who started school at age six or seven, the age equivalent of first or second grade entry for most American kids—not kindergarten. Plus, Hungarian parents had access to universal childcare prior to formal schooling, removing one of the largest barriers for U.S. parents trying to decide when to enroll their kid in public kindergarten at age five. This benefit does not apply to many American families facing heavy financial costs for delaying school. (A recent NWEA analysis on redshirting indicates a $12,000 cost for delaying school entry in the U.S.)
It’s also difficult to isolate the academic readiness aspect from competitive youth sporting culture in the U.S. When my own summer-birthday son approached kindergarten age, we were inundated with unsolicited advice from older family members worried about him being too small for sports. The term “redshirting,” after all, gets its name from the extra year of eligibility for college athletes. But student-athletes needing extra time to grow, train, and mature may be just as well off taking a gap year after high school.
Is there a viable policy solution to lessen the burden on families making this decision?
Short of subsidizing childcare costs to remove finances from the decision of what’s best for the child, states could consider a layered age cutoff system that guides parents toward thinking carefully about readiness for children who may be on the younger end of their grade level. As Reeves has written, elite private schools—serving families with the resources to make this decision under less financial pressure than the average parent—regularly encourage delayed entry for boys who are young for their grade. Incorporating a decision-making process into the standard rules for school entry nudges away from a system where wealthier families are guided to a better decision through off-the-record conversations.
Despite how fraught the decision can feel for parents, academic redshirting remains relatively rare. The NWEA analysis found that only about 5 percent of kindergartners delay entry, and the rate is effectively unchanged over the past 20 years. Whether this reflects what is best for children—especially boys—or structural barriers to doing what’s best for the child remains an open question.
SOURCE: Tímea Laura Molnár, “Can Academic Redshirting Shrink the Education Gender Gap? Causal Evidence on Student Achievement and Mental Health,” Journal of Human Resources (May 2026).
