Discussion prompt
20 minutes. A city plans a cash-support programme and says it will “raise happiness”. In 200 to 250 words, say what evidence from this module you would want before accepting that claim: which measure, which design, what size of effect and how long after the payment. Name one result that would change your mind.
Private: nothing you type here is sent or stored.
This course has no discussion board yet, so the prompt is a private reflection.
Recap
- Adaptation is real but differs by event; panel studies are needed to see it.
- Three studies on income differ in measure, method and the definition of a plateau; the 2023 collaboration reported rising emotional well-being for most people.
- Income works in proportions: equal steps per doubling.
- r² is the share of variation accounted for; predictors overlap.
- Confounders and reverse causation block causal claims; panels, natural experiments and randomised trials help, each with limits.
Module notes
Key terms. Hedonic adaptation: drift of feelings and judgements back toward an earlier level. Set-point idea: the claim of a stable personal baseline. Panel study: the same people measured repeatedly. Life evaluation: a rating of one’s life as a whole. Experience sampling: reports of feelings at random moments. Correlation (r): direction and strength of association, −1 to +1. r²: share of variation accounted for. Confounder: a third factor behind both measures. Reverse causation: the arrow points the other way. Natural experiment: a change outside people’s control.
Formulas. Faded share = (peak gain − remaining gain) ÷ peak gain. Change for an income ratio k = log₂(k) × points per doubling. Share of variation = r².
Limits of this module. Figures on income come from abstracts and later summaries and should be checked against the originals. The per-doubling rule and the percentage method are teaching simplifications.
References
- Brickman, P., Coates, D. and Janoff-Bulman, R. (1978). Lottery winners and accident victims: Is happiness relative? Journal of Personality and Social Psychology, 36, 917–927.
- Lucas, R. E. (2007). Long-term disability is associated with lasting changes in subjective well-being: Evidence from two nationally representative longitudinal studies. Journal of Personality and Social Psychology, 92, 717–730.
- Kahneman, D. and Deaton, A. (2010). High income improves evaluation of life but not emotional well-being. Proceedings of the National Academy of Sciences.
- Killingsworth, M. A. (2021). Experienced well-being rises with income, even above $75,000 per year. Proceedings of the National Academy of Sciences.
- Killingsworth, M. A., Kahneman, D. and Mellers, B. (2023). Income and emotional well-being: A conflict resolved. Proceedings of the National Academy of Sciences.
- Bennedsen, M. (2024). Preprint, arXiv:2401.05347 (a reanalysis of the income threshold question).
- Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences, 2nd edition. Lawrence Erlbaum Associates.