However, I find it to be extremely unlikely that the design of this study is sound. I'm not convinced that the scientific community even knows what all of the variables that determine your level of well being are, much less having the ability to account for them in a study like this.
As I have repeatedly stated elsewhere in this thread, in regions of the world with pervasive Internet access there are many, many factors that lead to increased well being, and conversely, in regions of the world without pervasive Internet access there are many, many factors that lead to decreased well being.
This study has accounted for some of the obvious variables here, but certainly not all of them.