Electoral Coalition Formation

1
Electoral Coalition Formation

• Project Author
• Sona Nadenichek Golder
• July 9, 2003

2
What Is an Electoral Coalition?

• In this study, denotes platform-like
• announcement by party headquarters
• During parliamentary election campaign,
• parties declare intent to govern together
• In district-based electoral systems,
• may involve joint coalition candidacies

3
Electoral Coalitions are Important . . .

• They shape electoral outcomes
• They clarify voters choices
• They precede 1 in 4 governing coalitions

4
Electoral Coalitions are Important . . .

• They shape electoral outcomes
• They clarify voters choices
• They precede 1 in 4 governing coalitions
• . . . But No One Studies Them

5
Electoral Coalition Model

• two strategic parties (A and B)
• one non-strategic party (Opp)
• winning joining post-election government
• coalition ? joint A-B campaign against Opp
• distinct ? three camps run distinct campaigns

6
Coalition Formation Game

• coalition
  coalition
• accept
  accept
• offer counter
• A B A
• 
  
• distinct
  distinct
• 
  coalition
• 
  accept
• offer
  
• B A
• 
  
• distinct
  distinct

7
When Will the Coalition Form?

• When coalition can offer each party more than
  its reservation value (distinct payoff)
• Payoffs based on generic pb expressions
• p probability of winning
• b office and policy benefits

8
Coalition is More Likely . . .

• the closer A and B are (ideologically)
• the farther A (or B) is from Opp (if coalition
  offers better odds of winning than distinct)
• the higher a coalitions odds of winning
• the lower As (or Bs) distinct odds of winning
  
• the smaller As (or Bs) distinct office
  benefits

9
Probit Coalition Propensity

• ?1 AB policy distance
• ?2 polarization ?3 ln(avg. magnitude)
• ?4 polarization ln(avg. magnitude)
• ?5 AB current seats
• ?6 (AB current seats)2
• ?7 percent upper tier seats
• ?8 disparity in A and B current seats
• ?0 ?

10
Among Dyads, Coalitions are Rare

• 74 of coalitions are two-party
• this tractability ? dyadic data
• among 4711 dyads
• (21 industrialized democracies
• 293 total election years),
• 238 (5) saw electoral coalitions

11
Results Support Hypotheses

• all model-derived coefficients are
  significant with proper sign
• increasing single variable value from mean to
  one standard dev. higher
• ? coalition likelihood increases between 5
  and 187 percentage points