Why do rational people vote in large elections with costs to vote ? Serge Blondel (GRANEM Univ....
-
Upload
sharyl-owen -
Category
Documents
-
view
217 -
download
1
Transcript of Why do rational people vote in large elections with costs to vote ? Serge Blondel (GRANEM Univ....
Why do rational people vote
in large elections with costs to vote?
Serge Blondel (GRANEM Univ. Angers & INH, CES)
Louis Lévy-Garboua (CES University Paris 1)
IAREP-SABE 08 Rome
Voting dec°
Non-EU
Examples
1
This result has not changed the behavior of people for who voting is a citizen obligation because this is the foundation
of a democracy.
American presidential election Bush-Gore:
each vote in Florida has counted.This issue is very rare, but this elcetion has recalled that it is possible.
We will study here the vote as a decision, as an alternative to abstention.
Voting dec°
Hyp.
Decision
Behaviour
Non-EU
Examples
2
Hypotheses considered here: - Preference for one candidate- Cost of voting - Probability of being decisive ε = ε1 + ½ ε2
ε1 : equality if no vote ε2 : equality if vote
Hypotheses NOT considered:- Taste for voting- Game theory solution Individual decision framework
Voting dec°
Hyp.
Decision
Behaviour
Non-EU
Examples
3
Owen& Grofman (84):
Voting dec°
Hyp.
Decision
Behaviour
Non-EU
Examples
4
EU : V A (1-ε).C < ε.(B-C) ε.B > CImpossible since ε≈0
Paradox of not voting (PNV) Downs 57
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a tq 1 - q - ε ε
A B 0 0
V B - C - C B - C
Voting dec°
Hyp.
Decision
Behaviour
Non-EU
Examples
5
Observed behaviours:- People do vote- The rate of participation increases with
the stake of the election- The rate of participation increases with
the uncertainty of the election
Ile-de-France - 2001
45%
50%
55%
60%
65%
70%
75%
45% 50% 55% 60% 65% 70% 75%
Rate of participation
Per
cen
tage
sco
re o
f th
e w
inn
er
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
6
=> non-EU theories (Starmer 2000): related to the previous results, not the PNV.
Paradoxes and anomalies of EU:- Gambling and insurance (Friedman &
Savage, 1948) - Allais paradox (Allais, 1953)- Preference reversal phenomenon
(Lichtenstein & Slovic, 1971)- Reflection effect (Kahneman & Tversky,
1979)...
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
7
Two hypotheses ignored by EU:H1: utility depends of the outcome
and the outcome in the alternative decision
H2: ε should be overestimated
N= 30 millions and q=50% => ε = 0.03%We pose:- B = 10- C = 1
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a t4 9 . 9 8 5 % 4 9 . 9 8 5 % 0 . 0 3 %
A 1 0 0 0
V 9 - 1 9
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
8
Ferejohn & Fiorina (74)Loomes & Sudgen (82)
Regret theory : EU + regretV A 4.0015 + 0.9997R(-1) + 0.0003 R(9) > 4.9985 + 0.9997R(1) + 0.0003 R(-9)
H1, not H2: impossible
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a t4 9 . 9 8 5 % 4 9 . 9 8 5 % 0 . 0 3 %
A 1 0 ( + 1 ) 0 ( + 1 ) 0 ( - 9 )
V 9 ( - 1 ) - 1 ( - 1 ) 9 ( + 9 )
Voting dec°
Non-EU Regret th.
Prospect Prospect th.th.
CC th.
Examples
9
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a t4 9 . 9 8 5 % 4 9 . 9 8 5 % 0 . 0 3 %
A 1 0 0 0
V 9 - 1 9
p
w(p)
1
10
Kahneman & Tversky (79)Quiggin (82)
Prospect theory :V A w(0.50015).9 - w(0.49985) >
w(0.49985).10
H2, not H1: impossible
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
10
Cognitive consistency theory – Lévy-Garboua 99: decision in two steps
1/EU maximisation 2/ Focus on the objection to EU
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a t4 9 . 9 8 5 % 4 9 . 9 8 5 % 0 . 0 3 %
A 1 0 0 0
V 9 - 1 9
Weighted average of : EU + objectionV A µ.4.0015 + (1-µ).9 > µ.4.9985 + (1-µ).0 , 0<µ≤1
µ<0.9003
H1 and H2: possible
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
11
General problem:V A µ.(εB-C) + (1-µ).(B-C) > 0
Prob (V A):- Increases with B- Decreases with C - Increases with ε- Decreases with µ
An “objection” to this theory: ε has a negligeable influence on the criterion. The impact of ε is marginal in relation with B,
C and µ. The weight of the objection is independent
from ε
N o t d e c i s i v e D e c i s i v e
V i c t o r y D e f e a tq 1 - q - ε ε
A B 0 0
V B - C - C B - C
Voting dec°
Non-EU Regret th.
Prospect th.
CC th.
Examples
12
V A µ.(εB-εC-(1-ε)C) + (1-µ).(B-C) > 0
(1-µ(1-ε)).(B-C) + µ.(1-ε)(-C) > 0
“w(1-ε)” “w(ε)”
The cognitive consistency theory explains the PNV and also the main paradoxes and anomalies of EU with only one extra parameter.
Voting dec°
Non-EU
Examples
13
THANK YOU for your attention !Questions?
Voting dec°
Non-EU
Examples
14