CAS PO 151 Lecture Notes - Lecture 3: Liberal Democratic Party (Japan), Wedge Issue, Party System
10 Aug 2018
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Department
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Professor
Party System Explanations: Institutional
Duverger’s Law: SMD produces a 2-party system.
o Two candidates should run, one from each party.
o Ex) the UK, located in the center of the two parties (Labour party vs. conservative party).
Proportional representation should produce multi-party systems
o Ex) Brazil
Mixed systems should be in between
Mechanisms:
o Mechanical (vote counting)
o Politicians’ career incentives
o Strategic voting
Party System Explanations: Sociological/Cleavage-Based
Cleavage: societal division defining different groups with fundamentally different interests and
identities
o Examples: religion, ethnicity, social class, etc
Party system should reflect cleavage structure
Party System Change Over Time?
Institutional
o Easy to explain change if electoral system changes
o Hard to explain change if it does not (ex: UK)
Sociological/cleavage-based
o Easy to explain long-term change in response to new cleavages (ex: rise of organized working
class)
o Hard to explain short-term change
Party System Change: Japan
1958-1993: Dominant Party System
o Liberal Democratic Party (LDP) almost always wins an absolute majority
1993-present: toward a 2-party system
o LDP and opposition alternate in power
o Single-party majorities in 2005, 2009
Why the change?
Reed’s Argument:
Electoral system change caused the party system change
1993 reform:
o Opposition wins under old system, pledges reform
o Old system (SNTV) facilitates one-party dominance
o New system is mixed like Germany’s
Expected effect: moved toward two-party or two-and-a-half party system
Party System Change: India
1947-1989: Dominant party system
o Congress Party (Indian National Congress) holds majority for all but three years 1977-1980
1989-present: multiparty system
o Two dominant parties but neither wins the majority
o No single third party completes a coalition
o Governing coalitions have included more than 10 parties
India: Party seat share of victorious electoral coalitions (graph)
Why Did India’s Party System Change?
No change in the electoral system: consistent Single Member Districts (SMD)
No change in cleavage structure
o Consistent ethnic diversity across states/regions
o Consistent diversity within caste system: Caste: system of social stratification combining class,
race, culture, and traditional occupation
Document Summary
Duverger"s law: smd produces a (cid:884)-party system: two candidates should run, one from each party, ex) the uk, located in the center of the two parties (labour party vs. conservative party). Proportional representation should produce multi-party systems: ex) brazil. Mechanisms: mechanical (vote counting, politicians" career incentives, strategic voting. Cleavage: societal division defining different groups with fundamentally different interests and identities: examples: religion, ethnicity, social class, etc. Institutional: easy to explain change if electoral system changes, hard to explain change if it does not (ex: uk) Sociological/cleavage-based: easy to explain long-term change in response to new cleavages (ex: rise of organized working class, hard to explain short-term change. 1958-1993: dominant party system: liberal democratic party (ldp) almost always wins an absolute majority. 1993-present: toward a 2-party system: ldp and opposition alternate in power, single-party majorities in 2005, 2009. Electoral system change caused the party system change.
