"Redshirting" is a term that describes college athletes who practice in red shirts but do not compete in games to receive an extra year of eligibility. Recently, the same idea has been applied to young kids entering school. More states than ever now require kids to turn 5 before they enroll in kindergarten, and more parents are voluntarily delaying their kids' entry into kindergarten.
In short, a small percentage of kids are being "redshirted."
In my opinion, the primary reason for kids being redshirted, especially in private schools, has to do with academic competition amongst schools. By putting kids in school later, they will be more mature, better able to sit still and do the work, and more likely to perform well. You don't have to be a rocket scientist to figure that out.
In 2009, The New York Times
(despite its liberal tendencies) published an article that bolstered redshirting:
"A report out of Cambridge University recommend[s] that kindergarten begin at the age of 6 rather than 5 in Britain. The Cambridge Primary Review is a sweeping study, requiring 14 authors, 66 research consultants, 28 research surveys, more than 1,000 'written submissions' and 250 focus groups, all leading to the conclusion that British children are currently not allowed to be children."
If you Google "what age should a kid start kindergarten," you're going to see a lot of obfuscating and confusing information. That's because it's a political thing. The liberal mentality is that kids should be taken out of the home and provided with government education ASAP. I find that scary. That is not in the best interest of children. As the Cambridge study points out, kids simply need to be allowed to be kids. If you ask really good teachers about this, they will almost always tell you not to put your kids in school too early. The effects of starting too young begin showing up right around the third grade when kids get knocked off their feet because they're not really ready. Boys are especially unprepared because they take longer to mature neurologically and emotionally.
I think kids should be allowed to be kids, and I believe parents should restructure their families so they're able to raise their kids. People should postpone having kids until they can do the right thing by them. It's the same principle as buying car: if you can't really afford the upkeep and monthly fees, don't go out and buy one. Don't put children in an awkward situation simply because you're not ready to handle it. It's not right. Most people have the biological ability and legal right to have kids, but that doesn't give them a moral right. People who aren't responsible shouldn't have kids.
One of the main complaints about redshirting comes from parents who don't want to have to pay for an extra year of child care. Seriously?! They'll put their kids in school at 4 if it will cost them less? Apparently they don't care what's in the best educational interest of children.
Of course, some kids will be ready for school earlier than others, but for the most part, we shouldn't be forcing them into school at age 4. Homeschool them, and when they start kindergarten, they'll be stars. I'm all for kids not starting kindergarten until the age of 6. Let them be kids.