The Jagiellonian compromise is an electoral system for two-tier voting bodies originally proposed in 2004[1] for the Council of the European Union as a way of achieving "one person, one vote" within the union.
The compromise was analysed by various authors[2] and received attention in the popular press.
[3] The system is based on the square root law of Penrose, which implies that a priori voting power defined by the Penrose–Banzhaf index of a member of a voting body is inversely proportional to the square root of its size.
Hence the number of votes obtained by a representative of a state
Jagiellonian Compromise is based on a single criterion only.
member states is taken if the sum of the weights of states voting in favour of a given proposal exceeds the qualified majority quota
equal to For a generic distribution of population among
states of the union, the optimal threshold