Valuing and wisely using free time is a skill. Seems like this study is just measuring people's lack of training in that skill. Something like: "we found that

Valuing and wisely using free time is a skill. Seems like this study is just measuring people's lack of training in that skill. Something like: "we found that adding grand pianos to houses improves the overall pianism, but the effect levels out at about three pianos per neighborhood."