Many California retailers know the name "John Vasconcellos." John was a highly popular California State Assemblyman from 1967 to 1997—becoming chairman of the influential Assembly Ways and Means Committee—and then a California State Senator for 8 years, not running for reelection in each case only because of term limits. But to those outside California, he might be best known as the founder of the California Task Force to Promote Self Esteem and Personal and Social Responsibility. John, a firm advocate of positive psychology, pushed forward legislation to fund programs based on the idea that raising teenagers' good feelings about themselves would make them behave more responsibly.
John did insist that since taxpayer money was being spent, the programs should be rigorously evaluated. It turned out that teenage gang leaders whose self-esteem was raised did not change their criminal behaviors much. They kept up the stealing, beatings, and revenge killings. It's that they felt better about themselves while doing it all.
John Vasconcellos was ridiculed. California government funding for those programs ended.
As far as I know, evaluators of the Vasconcellos-sponsored California programs never looked at the relationships between increasing teenagers' self-esteem and their retail buying habits. This mantle was assumed more recently by some Illinois and Minnesota researchers who discovered that when teenagers are praised for their legitimate accomplishments, those teenagers become less likely to make foolish retail purchases.
Retailers who come to know their teenage customers and then learn about their academic, sports, and other large and small victories can help create repeat shoppers for the long term by giving justified praise. The teens are bound to blush and stammer when praised, but they'll buy more wisely. Their families, and eventually the teens themselves, will end up appreciating you for that.