The measurement of political efficacy has been one of the most contested debates in survey research methodology and public opinion since Campbell et al. defined the concept in 1954. Despite the great deal of attention generated by the debate and controversy around its measurement, no general agreement has been reached to the date. However, this lack of agreement did not prevent the concept from being exported to a variety of political contexts without assessing the constructs’ external validity. In this paper we use data from the United States and United Kingdom to assess through Multigroup Confirmatory Factor Analysis (MGCFA) the external validity of the pilot survey items designed by Craig, Niemi and Silver (1990), its cross – national invariance and its correlates with different modes of Political Participation in the US and UK.
