3 Alois Stutzer and Bruno S. Frey, ‘What Happiness Research Can Tell US About Self-Control Problems and Utility Misprediction’, IZA Discussion Paper no. 1952 (January 2006).
4 Elizabeth W. Dunn, Daniel T. Gilbert and Timothy D. Wilson, ‘IF Money Doesn’t Make You Happy, Then You Probably Aren’t Spending It Right’, Journal of Consumer Psychology, vol. 21, issue 2 (April 2011).
5 Zhanjia Ahang and Weiyun Chen, ‘A Systematic Review of the Relationship Between Physical Activity and Happiness’, Journal of Happiness Studies (24 March 2018).
6 皮尤研究中心（Pew Research Center），Are We Happy Yet (February 2006).
7 Sonja Lyubomirsky, Kennon M. Sheldon and David Schkade, ‘Pursuing Happiness: The Architecture of Sustainable Change’, Review of General Psychology, vol. 9, no. 2 (2005).
8 皮尤研究中心，People in Emerging Markets Catch Up to Advanced Economics in Life Satisfaction (October 2014).
9 Richard A. Easterlin, Laura Angelescu McVey, Malgorzata Switek, Onnicha Sawangfa and Jacqueline Smith Zweig, ‘The Happiness-Income Paradox Revisited’, Proceedings of the National Academy of Sciences, vol. 107, no. 52 (28 December 2010).
10 Sonja Lyubomirsky, Kennon M. Sheldon and David Schkade, ‘Pursuing Happiness: The Architecture of Sustainable Change’, Review of General Psychology, vol. 9, no. 2 (2005).
11 美国日常生活的快乐程度在收入达到七万五千美元时为最高点。参考来源：Daniel Kahneman and Angus Deaton, ‘High Income Improves Evaluation of Life But Not Emotional Well-Being’, Proceedings of the National Academy of Sciences, vol. 107, no. 38 (21 September 2010)。一项针对一百六十四个国家、总计一百七十万人的调查研究，也得出六万到七千五百万美元之间的类似结果。资料来源：Andrew T. Jebb, Louis Tay, Ed Diener and Shigehiro Oishi, ‘Happiness, Income Satisfaction and Turning Points Around the World’, Nature Human Behavior, vol. 2, 33-38 (January 2018)。
12 Daniel Kahneman, Alan B. Krueger, David Schkade, Norbert Schwartz and Arthur A. Stone, ‘Would You Be Happier If You Were Richer A Focusing Illusion’, Science, vol. 312 (June 2006)
13 Daniel Kahneman and Angus Deaton, ‘High Income Improves Evaluation of Life But Not Emotional Well-Being’, Proceedings of the National Academy of Sciences, vol. 107, no. 38 (21 September 2010)
14 David Schkade and Daniel Kahneman, ‘Does Living in California Make People Happy ’ Psychology Science, vol. 9, no. 5 (September 1998).
15 Erzo F. P. Luttermer, ‘Neighbors as Negatives: Relative Earnings and Well-Being’, Quarterly Journal of Economics (August 2005).
16 John Gathergood, ‘Debt and Depression: Casual Links and Social Norm Effects’, The Economic Journal (September 2012).
17 Daniel Kahneman, Alan B. Krueger, David Schkade, Norbert Schwartz and Arthur A. Stone, ‘Toward National Well-Being Accounts’, AEA Papers and Proceedings (May 2004).
18 Huffington Post.com, ‘Divorce Study Shows That couples With Longer Commute Are More Likely to Divorce’ (13 August 2013).
19 Leaf Van Boven and Thomas Gilovich, ‘To Do or Have That Is the Question’, Journal of Personality and Social Psychology, vol. 85, no. 6 (2003)
20 Kim Parker, Parenthood and Happiness: It’ More Complicated Than You Think, Pew Research Center (7 February 2014).
21 Chris M. Herbst and John Ifcher, ‘The Increasing Happiness of Parents’, Review of Economics of the Household (July 2015).
22 Angus Deaton and Arthur A. Stone, ‘Evaluative and Hedonic Wellbeing Among Those With and Without Children at Home’, Proceedings of the National Academy of Sciences, vil. 111, no. 4 (28 January 2014).
23 Elizabeth W. Dunn, Daniel T. Gilbert and Timothy D. Wilson, ‘IF Money Doesn’t Make You Happy, Then You Probably Aren’t Spending It Right’, Journal of Consumer Psychology, vol. 21, issue 2 (April 2011).
24 Richard M. Ryan and Edward L. Deci, ‘Self-Determination Theory and the Facilitation of Intrinsic Motivation, Social Development, and Well-Being’, American Psychology, vol. 55, no. 1 (January 2000).
25 我真的很想说就是HumbleDollar.com，做为注释不算太刻意吧。
26 Ashley V. Whillans, Elizabeth W. Dunn, Paul Smeets, Rene Bekkers and Michael I. Norton, ‘Buying Time Promotes Happiness’, Proceedings of the National Academy of Sciences, vol. 114, no. 32 (8 August 2017).
27 Daniel Kahneman, Alan B. Krueger, David Schkade, Norbert Schwartz and Arthur A. Stone, ‘Toward National Well-Being Accounts’, AEA Papers and Proceedings (May 2004).
28 Julianne Holt-Lunstad, Timothy B. Smith and J. Bradley Layton, ‘Social Relationships and Morality Risk: A Meta-Analytic Review’, PLOS Medicine (27 July 2010). PLOS是公共科学图书馆（Public Library of Sci-ence）的缩写。
29 写给那些吹毛求疵的人：我们只计算格洛佛．克里夫兰（Grover Cleveland）一次，虽然他曾两度担任总统。直至二○一八年中，有四十五任美国总统，但只有四十四位总统。
