"The problem is children’s clothing manufacturers cling to their 30+ year old size charts. They protect their sizing information like a trade secret (not uncommon in every segment of the fashion biz). And while major studies are being done on men and women, they are not being done on children. (If I am wrong, please let me know)."After doing some more reading at fashion-incubator, I discovered I am only half right. The 30 year old study on children's measurements done in 1975/1977 is publically available here: Anthropometric Data of Children. This is the data that most manufacturers continue to use. Since it is freely available, there is not much incentive to change. I have been using size chart information based on this data for at least 10 years because this is what the companies I worked for used. To be fair, it is still fairly good information.
Another source for sizing information is available from ASTM International. Kathleen Fasanella at fashion-incubator.com lists the documents to search for at her blog: How to obtain sizing and grading info. This data set is updated about every five years or so. Even though the data information is priced fairly, you still need to buy 3 charts to cover all children infant through teenagers, a price of about $90. The other thing to consider when purchasing from ASTM is that you only license the information. Be sure to read the license agreement! You are given permission to download on one computer and print out only ONE copy of the charts. You also give permission to ASTM to come and inspect your company computer and materials at any reasonable time to ensure you are complying.
As a small company, I do not like this license agreement. What if I have two or three technical designers who need access to this chart? My costs for this information multiplies! Plus, who wants to allow some other company/organization to come in and inspect your premises at will?! I wonder if ASTM has ever tried to enforce their license?
I also don't like the propriatary nature of the data. The only way to get cooperation from businesses to standardize is to make the information available for free. I realize as an organization they need to make money to support a needed role. But they could take a hint from other opensource projects and raise money by donation or some other model.
Because of the difficulty with ASTM, I now understand why companies continue to use 30 year old data.