The purpose of this study was to examine measurement invariance of the Subjective Happiness Scale across countries, gender, and age groups and across time by multigroup confirmatory factor analysis. Altogether, 4,977 participants from nine European, American, and Australian countries were included in the study. Our results revealed that both configural and metric invariance held across countries, but scalar invariance was only partially confirmed with one item yielding varying intercepts in different countries. Measurement invariance was also confirmed across gender and age groups. Longitudinal measurement invariance was examined on a subsample of 478 English-speaking participants and was fully confirmed across five consecutive assessment points. Factor means were compared between groups and across time, and good convergent validity of the Subjective Happiness Scale was found in relation to a measure of temporal satisfaction with life. Overall, our results demonstrate that self-reported happiness was measured similarly in nine different countries, gender and age groups and over time, and provide a solid foundation for meaningful cross-group and cross-time comparisons in subjective happiness.
Keywords: Subjective Happiness Scale; group comparison; happiness; longitudinal measurement invariance; measurement invariance; well-being.