The Age Trajectory of Happiness: How Lack of Causal Reasoning has Produced the Myth of a U-Shaped Age-Happiness Trajectory
The Age Trajectory of Happiness: How Lack of Causal Reasoning has Produced the Myth of a U-Shaped Age-Happiness Trajectory
A large interdisciplinary literature on the relationship between age and subjective well-being (happiness) has produced very mixed evidence. Virtually every conceivable age-happiness trajectory has been supported by empirical evidence and theoretical arguments. Sceptics may conclude that the social science of happiness can only produce arbitrary results. In this paper we argue that this conclusion is premature. Instead, the methodological toolbox that has been developed by the modern literature on causal inference gives scholars everything they need to arrive at valid conclusions: the causal inference toolbox only must be applied by happiness researchers. We identify four potential sources of bias that may distort the assessment of the age-happiness relationship. By causal reasoning we derive a model specification that avoids these biases. For an empirical illustration, we use the longest running panel study with information on happiness, the German Socio-Economic Panel (1984-2017; N persons=70,922; N person-years =565,703). With these data we demonstrate the relevance of the four biases and how combinations of different biases can reproduce almost any finding from the literature. Most biases tend to produce a spuriously U-shaped age trajectory, the most prominent finding from the literature. In contrast, with our specification we find a (nearly monotonic) declining age-happiness trajectory.