School administrators and teachers create a culture for high learning and achievement when they partner with parents to make decisions regarding the optimal age to begin formal schooling. The age that students begin school has decreased across the globe; however, the United States has various eligibility dates for school entry that require children to begin kindergarten at older ages. A large amount of research suggests that there is an achievement gap between students whose ages are close to the eligibility age for school entry when they begin kindergarten compared to students who begin kindergarten at an older age. Parents often attempt to reduce the potential that their young children will experience school failure by "redshirting" them for a year before enrolling them in kindergarten; however, many parents cannot afford to pay for another year of childcare so they enroll their children in kindergarten with the possibility of retaining them and repeating kindergarten. Some researchers assert that there are no positive long-term effects to redshirting children. Children grow and develop at various rates; therefore, parents and educators must collaborate to decide when a child will begin public school based on individual social, emotional, and academic needs.