Abstract
The paper uses paradata on response time, cognitive effort and questionnaire order from a large Dutch internet panel survey to study the association between reporting process and reported happiness. We find that slower responses and higher self-stated cognitive effort are associated with lower reported happiness, potentially, because they proxy for momentary mood. Moreover, in multivariate happiness equations, these factors moderate the estimated effect of income on happiness, while no interaction effects are found for other socio-economic determinants of happiness. Our findings have implications for the interpretation of relative marginal effects in economic happiness equations.