رضایت از زندگی، درآمد و شخصیت

We use personality traits to better understand the relationship between income and life satisfaction. Personality traits mediate the effect of income on life satisfaction. The effect of neuroticism, which measures sensitivity to threat and punishment, is strong in both the British Household Panel Survey and the German Socioeconomic Panel. Neuroticism increases the usually observed concavity of the relationship: individuals with a higher neuroticism score enjoy extra income more than those with a lower score if they are poorer, and enjoy extra income less if they are richer. When the interaction between income and neuroticism is introduced, income does not have a significant effect on its own. To interpret the results, we present a simple model based on Prospect Theory, where we assume that: (i) life satisfaction is dependent on the gap between aspired and realized income, and this is modulated by neuroticism and (ii) income increases in aspirations with a slope less than unity, so that the gap between aspired and realized income increases with aspirations. From the estimation of this model we argue that poorer individuals tend to over-shoot in their aspirations, while the rich tend to under-shoot. The estimation of the model also shows a substantial effect of traits on income.

Given its importance for welfare analysis and public policy, the general relation between self-reported well-being and personally available income has been widely investigated. A regression of life satisfaction on income using both cross-sectional and panel survey data from a developed country generally shows a significant, positive, but small estimated coefficient of income (e.g. Blanchflower and Oswald, 2004 and Ferrer-i-Carbonell and Frijters, 2004). Although the debate on the existence of a satiation point is still open, there is general agreement that the size of the effect is decreasing with income, consistent with the usual assumptions on the utility function of individuals, as Layard, Mayraz, and Nickell (2008) explicitly point out.2 However, a significant amount of evidence suggests that the link between income and life satisfaction is more complex than that. Life satisfaction appears to be monotonically increasing with income when one studies this relation at a point in time across nations (e.g. Di Tella and MacCulloch, 2010 and Stevenson and Wolfers, 2008). Over time, however, the relation between GDP and life satisfaction appears rather different. In a well-known finding, Easterlin reports no significant relationship between happiness and aggregate income in time-series analysis. For example, the income per capita in the USA in the period 1974–2004 almost doubled, but the average level of happiness shows no appreciable trend upwards. This puzzling finding, appropriately called the Easterlin Paradox (Easterlin, 1974) has been confirmed in similar studies by psychologists (Diener, Diener, & Diener, 1995) and political scientists (Inglehart, 1990), and has been shown to also hold for European countries (Easterlin, 1995).3 A recent paper by Proto and Rustichini (2013) finds a positive relationship between growth and satisfaction for countries with a GDP below 15,000 USD but shows that this relationship is flat in richer countries, suggesting a gap between aspiration and realized income. A potential explanation of the paradox is that individuals adapt to current conditions, and the level of subjective well-being tends to revert to a baseline level depending on a reference point, an idea originally proposed by Brickman and Campbell (1971). Aspirations are naturally associated with the reference point provided by current income. Hence, to the extent that an increase in income leads to an increase in aspirations, changes in income may not have a long-run effect on subjective wellbeing.4 Another explanation of the Easterlin Paradox hinges on the concept that relative, rather than absolute income, is the main determinant of life satisfaction, an idea that can be dated back to Duesenberry (1949). The two explainations are closely related.5 The present paper aims to shed more light on the relation between personal income and life satisfaction by analyzing how personality affects this relation. Recently, economists have recognized the importance of introducing personality traits into economic models (Borghans et al., 2008, Rustichini, 2009 and Almlund et al., 2011). Recent studies show that personality has a biological basis, as DeYoung and Gray (2010) argue in an exhaustive survey of the literature. The rest of the paper is organized as follows. In Section 2 we describe the datasets, the main variables (2.1) and the econometric model (2.2). In Section 3 we show the results from the estimation of the econometric model. In Section 4 we describe our theory and estimate the structural model (4.1). In Section 5 we conclude by highlighting the main results. Additional analysis and more technica l details are in the appendix.