Karl Smith is the Assistant Professor of Public Economics at UNC-Charlotte, and he has studied retail employment over the past 20+ years. Given that retail sales have, in real dollars, risen nearly 40% since 1990, he posits that retail employment of teenagers (age 16-19) should be higher than it is.
In his article, What the 'End of Retail' Means for Young Workers, Dr. Smith ignores the fac that the minimum wage has gone up over that same period. Young people first entering the workforce are the least productive and least valuable workers in the world. Yet, the government has made it more and more expensive to hire them. Hiring less of them is a perfectly rational and predictable response by retailers.
The fastest way to get young people int the workforce and contributing to society is to eliminate the minimum wage. But the unions won't allow that to happen.