The Politics of (Re-)Apportionment of the European Parliament: The Union Law vs Reality

The paper presents a diachronic analysis of apportionment of seats in the European Parliament since its foundation to the present and beyond, up to the upcoming European elections. Its goal is to quantify the degressive proportionality principle to answer whether there has been a degressive representation in the European Parliament. The analysis employs statistical tools commonly used for measuring electoral disproportionality; at the individual level, both the value of a vote (the average size of population per seat) and the advantage ratio (the rate of over-/under-representation of each Member State) are measured, while at the aggregate level, the value of malapportionment is measured (by the adaptation of the Distortion index). The paper concludes that there is no degressive representation in the European Parliament since 2004 while degressivity had been achieved until the 2004 elections. However, re-apportionment of seats for the upcoming elections due to Brexit approximated to the degressive proportionality principle although there is an exception to the rule which is mainly because there has been an informal agreement that no Member State must have fewer representatives in the European Parliament than it was the case of the 2014 European elections.