A cross-cultural evaluation of the Personal Wellbeing Index – school children in samples of Australian and Portuguese adolescents

The practice of comparing nations on subjective wellbeing (SWB) is becoming commonplace, with many countries ranked by economists and social scientists alike according to average levels of SWB based on survey responses. Such large, multi-national population surveys have the potential to generate insights into the causes and correlates of SWB within different cultural groups, as well as inform policy regarding how to improve the wellbeing of citizens. At the heart of these large-scale research endeavors are SWB measures that function equivalently between the various participating cultural groups. For this reason, it is concerning that their remains a paucity of research that supports measurement equivalence for many SWB instruments commonly employed. Thus, it remains unclear whether variations in SWB across cultures reflect true differences, or whether these differences reflect measurement biases (e.g., response bias inherent within a particular cultural group). The aim of this study was to examine the psychometric equivalence of the Personal Wellbeing Index–School Children (PWI-SC) in convenience samples of Australian and Portuguese adolescents using multiple-group confirmatory factor analysis. Participants comprising the Australian sample were 1104 Victorian high-school students aged between 12 and 19 years (M = 14.42, SD = 1.63). Participants comprising the Portuguese sample were 573 high-school students living in Portugal aged between 12 and 18 years (M = 14.32, SD = 1.72). The results demonstrated strict factorial invariance between both versions of the PWI-SC, suggesting that this scale measures the same underlying construct in both samples. Moreover, these findings provide preliminary support for quantitative comparisons between Australian and Portuguese adolescents on the SWB variable as valid.