Both 22B and Blackcat make good points.
This is another summary of some of the research.
http://www.wcer.wisc.edu/news/coverStories/pros_cons_holding_out.phpIt is interesting that is primarily boys that are red shirted and that some parents apparently make the decision at birth, so they are not waiting to make a judgement based on their child's actual level of school readiness or behaviour when they turn 5 or 6.
When red shirting is a pervasive attitude in the community then it can become one more argument against acceleration for gifted kids. Although it was interesting to read that when some red shirted students hit school their parents found themselves pushing for a more advanced curriculum as their children become frustrated with the level and pace of kindergarten.
If schools weren't all about age grouping for academic progress perhaps the arguments about red shirting would occur less. Students could just attend the class level that best met their needs.
