In this project we seek to understand the variation in the activity of MPs and their performance as representatives in parliamentary systems. Our goal is to understand how representatives work in order to assess their performance in office. We are seeking explanations for the differences in activities which cannot be explained by educational attainment or experience. We aim to better understand how MPs work to represent their constituencies and where they rather serve the party. The importance of a functioning and stable parliament with MPs who are active and responsive to voters is one of the corner stones of the sixteenth of the UN Sustainable Development Goals of the 2030 Agenda: “Peace, Justice, and Strong Institutions”. Peaceful societies depend on  strong institutions where citizens voices are represented by their MPs. In political systems with strong parties, MPs face two principals - voters and the party. Thus, MPs will need to find ways to differentiate themselves from other MPs, for example, by co-sponsoring bills using the room for maneuver granted by parties (Calca/Koehler, 2021a; Calca/Koehler, 2021b; Calca, 2022). To study the way MPs use this space and assess their relative effectiveness, we will analyze co-sponsorship activities in Portugal and Ireland. The former is characterized by a closedlist electoral system, the latter by a single transferable vote system. They provide us with variation on electoral institutions and have strong parties. We use the institutional variation to adjust the Legislative Effectiveness Score developed for the US by Volden and Wiseman (2014), to be applicable in proportional systems. A novel approach and clear measurement model is used to re-conceptualize parts of the score. We call the revised score Legislative Effectivenes Score for Proportional Systems (LESPS). For the construction of the LESPS score, our main dependent variable, we collect both quantitative data on MPs’ co-sponsorship activities and media attentio...