[1] https://www.google.com/search?q=research+suggests+that+happi... [2] http://www.usc.edu/dept/pubrel/trojan_family/winter07/happin... [3] http://vanneman.umd.edu/socy699J/GrahamP02.pdf [4] http://isites.harvard.edu/fs/docs/icb.topic620591.files/Indi... [5] Relative Income Hypothesis. I will leave the googling of this as an exercise for the reader.
[1] https://www.google.com/search?q=research+suggests+that+happi... [2] http://www.usc.edu/dept/pubrel/trojan_family/winter07/happin... [3] http://vanneman.umd.edu/socy699J/GrahamP02.pdf [4] http://isites.harvard.edu/fs/docs/icb.topic620591.files/Indi... [5] Relative Income Hypothesis. I will leave the googling of this as an exercise for the reader.