a. Notwithstanding this analysis, the main drawback of hybrid systems lies in their complexity. Doubtless, some “simple” systems, such as proportional representation, are in themselves very complicated when it comes to the way in which seats are distributed, especially in the use of remainders, for an elector who is not arithmetically minded. But at least their underlying principle is unambiguous and everybody can grasp it straight away. That is not the case with hybrid systems, which often involve procedures that distort the results of the ballot boxes so as either to exclude certain votes from representation (through the operation of thresholds) or, on the contrary, to increase the weight of other votes (the majority bonus, for example, for the leading party). The elector who has difficulty in understanding the complexity of the arithmetic will find it even more difficult to accept the resulting discrepancy compared to the votes cast. This may lead sometimes, or even often, to a feeling of alienation vis-à-vis the operation of the electoral system, which is “manipulated by politicians”.

b. To this difficulty can be added that of the nature of the “mix” itself. A hybrid system would be paralysed or simply random if the various logics it combined did not involve an appropriate ranking. But only experience can help in choosing the correct mix. If the secondary logic is instilled too weakly, it will scarcely have any corrective effect on the result of the election. If, conversely, it is too strong, the main logic system will be diluted to an excessive extent. The problem is particularly acute when a quantitative correction factor has to be introduced in order, for example, to set the level of a majority bonus or the threshold required to be surpassed in order to be represented.

c. In order to overcome these kinds of difficulties, the Committee for the Reform of theVoting Method, set up in France in 1992 by Prime Minister Pierre Bérégovoy, on which Alain Lancelot sat under the presidency of Professor Vedel, proposed maintaining the majority system  with two rounds of voting for most of the seats in the Assemblée nationale and adding, “for non-negligible part” of those seats, the election by proportional representation of national lists.
The representatives of the left-wing majority and the right-wing opposition sitting alongside theexperts on that committee finally agreed that 10% of the total number should constitute the “nonnegligible part” of national seats to be filled by proportional representation, but only after bitterly debating the very principle of a hybrid system, since they were concerned that it would look like a return to “rule by political parties”. The argument that finally won them over was our proposal that each elector should be given two votes: the first to elect one of the candidates in the singlemember majority ballot, and the second so as to choose one of the lists of candidates by proportional representation at the national level. The originality of this hybrid system lay in its transparency, since having a double vote would definitively preclude any accusation of inequality and any suspicion of distorting the will of the electorate. But the idea ultimately ran aground owing to the practical difficulty in finding fifty seats to be filled by proportional representation, either by increasing the total number of seats, which, in the eyes of the parliamentarians on our committee, ran the risk of worsening anti-parliamentary feeling, or else by reducing by the same amount the number of constituency seats, which would be very unpopular in the départements whose representation would be reduced. And the reform was not taken on board by the Government. In France, we like to say that “the devil is to be found hiding in the details” and hybrid systems, alas, do not lack detail.