Political Efficacy Short Scale (PESS)
The Political Efficacy Short Scale (PESS) is the English-language adaptation of the German-language Political Efficacy Kurzskala (PEKS); it measures perceived political efficacy with four items. PESS comprises two subscales—internal and external political efficacy—with two items each. Internal political efficacy refers to the belief in one's own political effectiveness; external political efficacy refers to the belief in the responsiveness of the political system to citizens' concerns. Completion time for all four items is less than 30 s. The items of the German-language source version were translated into English using the TRAPD approach. The present study empirically validated the English-language adaptation (PESS) based on a heterogeneous quota sample in the UK. The results show that the reliability and validity coefficients of the English-language adaptation are sufficiently high and that they are comparable to those of the German-language source version. In addition, the scale showed strict measurement invariance (i.e., equal loadings, intercepts, and uniquenesses) when comparing the UK and Germany, which indicates the comparability of manifest scale scores (means and variances) and correlations across the two nations. As a short scale, PESS lends itself particularly to the measurement of political efficacy in survey contexts in which assessment time or questionnaire space is limited. It is applicable in a variety of research disciplines, including political science, sociology, psychology, and economics.