GDP and various economic outputs are a poor measure of a countries "success" and needs to be dropped asafp.
A better measure would be median income per capita minus median cost of living. Giving a more accurate view of "success" if success is defined as the quality of living for a countries inhabitants.
Yes there is the age old argument of money doesnt bring happiness but not being able to afford a roof and 3 square meals tends to make being happy more difficult.