Cambridge Compromise - Between Equality and Proportionality

The problem of allocating seats in the European Parliament among EU member states is still open. The principle of degressive proportionality which is incorporated into the Lisbon Treaty offers so much room to maneuver, that it decides on how the composition of the European Parliament during subsequent terms only to a certain extent. This paper examines the principle of degressive proportionality, showing how from the mathematical point of view it is located between equal and proportional division. The paper suggests, furthermore, a way of measuring to what extent the division of seats is equal and to which proportional. The analysis carried out in the context of the Cambridge Compromise, where a group of mathematicians (invited by Parliament) has submitted a proposal for a long-term solution to the problem of allocation of mandates