Developing an item pool and testing measurement invariance for measuring public service motivation in Korea

In a recent study, an international measure of public service motivation (PSM) failed to achieve measurement invariance across cultures and languages. However, since that research was able to confirm the four-dimensional structure of PSM, it can provide a starting point for studying PSM in a single country. This study aimed to develop an item pool for measuring PSM in Korea. Online survey data (n = 1800), collected from both the public and private sectors, were used to test measurement invariance to validate the use of the measure across genders and sectors. The results provide support for both the initial four-dimensional 29-item PSM model and the more concise 16-item PSM model, confirming that the dimensions have the same meaning and scaling across genders and sectors in Korea. This study may be the first to test the measurement equivalence of a PSM measure across different groups in a single country.