1. Electoral Systems and Party Systems - A Two-Way Relationship Daniel BUTI

2. Theoretical premises
Maurice Duverger ("Les partis politiques", 1951) - the effects of electoral systems on party systems: three sociological laws.
There is a rich literature that challenges, applies, checks, confirms or tones down Duverger's classical theory.
Regardless of the approach, the discussion starts from the existence of a relationship, with varying intensities, between the electoral systems and the party systems, which is unidirectional: from the electoral system to the party system.

3. Statements
In the electoral system - party system relationship a variable must be introduced and taken into account: the political configuration;
Between the electoral system and the party system there is a two-way relationship; it can also work in reverse.
I support these allegations through a brief analysis of the parliamentary elections.

4. Electoral Formula
Law no. 35 / 2008: Deputies and Senators are elected by uninominal vote, according to the principle of proportional representation, in uninominal colleges.
Allocation of the seats is a two stages process:
At the level of electoral constituency;
At national level.
Assignment of the seats is a two stages process:
In the uninominal college, with an absolute majority of votes;
In the electoral constituency, based on proportional representation.
The law provides a mechanism to ensure proportionality through compensation - a complex proportional compensatory system.

5. Parliamentary Election Results 2008
Electoral competitor
CHAMBER OF DEPUTIES
SENATE
VOTES
SEATS
No. % 1.
PSD+PC
33.09
114
34.13
34.16 49
35.76 2.
PD-L
32.36
115
34.43
33.57 51
37.22 3.
PNL
18.57 65
19.46
18.74 28
20.43 4.
UDMR
425008
6.17 22
6.58
440449
6.39 9
6.56
Total
100
334*
137
*Organizations of citizens belonging to national minorities
Total number of registered electors:

6. The Format of the Party System
The effective number of parties (N=1/Σs²):
N = 3.27
Multiparty system with dominant party
Bipolarization tendency

7. Parliamentary Election Results 2012
Electoral competitor
CHAMBER OF DEPUTIES
SENATE
VOTES
SEATS
No. % 1.
USL
58.63
273
66.26
60.10
122
69.31
PSD
160
38.83 64
36.36
PNL
100
24.27 50
28.40 PC 13
3.15 8
4.54 2.
ARD
16.50 56
13.59
16.70 24
13.63 3.
PP-DD
13.99 47
11.40
14.65 21
11.93 4.
UDMR
380656
5.13 18
4.36
388528
5.23 9
5.11
Total
412*
176
* Organizations of citizens belonging to national minorities
Total number of registered electors:

8. The Format of the Party System
The effective number of parties: N = 2.02
A defective two-party system
Major imbalance of the party system. The bipolar tendency observed in 2008 is no longer valid

9. Conclusions One electoral system – two party systems;
This reality questions the general thesis of the one way relationship between electoral system and the party system.
Answer: introducing a variable - the political background;
The difference between the two analyzed party systems is due to this new variable;
In terms of comparative analysis, the electoral system acts as a dependent variable.