Mobilization and Participation: A Natural Experiment

1. Mobilization and Participation: A Natural Experiment Yusaku Horiuchi (ANU) Kentaro Fukumoto (Gakushuin Univ.) SPM Summer 2009

2. Mobilization and participation • Mobilization theory • Voters go to the polls when they are asked to do so (Rosenstone and Hansen 1993). • A natural experiment in Japan • Unusually small vote margin • Unusual (near) random treatment assignment • Usual dependent variable (turnout) & unusual dependent variable (relocation)

4. Closeness in municipal assembly elections in Japan

5. How to test it? • Observational studies • Endogeneity • Randomized field experiments • A specific type of mobilization • U.S. as a case in mostexisting studies • Natural experiments • A rationale behind the key assumption • Unexpected consequences of the treatment

6. Japanese local elections • Simultaneous local elections (SLEs) • Since 1947, in principle, the 2nd (prefectural elections) and 4th (municipal elections) Sundays in April, in every fourth year • “Dropped out” due to events in the distant past or non-political reasons, such as … • Municipal mergers in the 1950s • Death of mayor

9. Two treatments • Executive treatment (ET) • 1 if a mayoral election was held on April 27, 2003, and 0 otherwise • 2003 SLEs: 21% treated, 79% control • Legislative treatment (LT) • 1 if a municipal assembly election was held on April 27, 2003, and 0 otherwise • 2003 SLEs: 53% treated, 47% control

10. Study #1: Turnout • Outcome variable • Voter turnout in prefectural assembly elections held on April 13, 2003 (i.e., two weeks before municipal elections) • A variant of “coattail” effect • Mobilization for their fellow candidates • De facto mobilization for their own votes • Large effect in municipal assembly elections

11. Balance test • Propensity scores • Unselectively, use all available variables in a collection of statistics the government publishes annually (N=96). • Blocking by districts for prefectural assembly elections: at least one treated and one untreated within each district • Subclassification (20 subclasses)

13. Treatment effects

14. Study #2: Relocation • Outcome variable • Moving-in population (the log ratio to the same month in the previous year) • Unusual mobilization • Mobilization of friends and relatives living outside the boundary of an electoral district. • Rumors, arrests, judicial decisions, … but never empirically investigated

15. Institutional settings • Two key constraints • Must live in three consecutivemonths in a municipality before the voting day (e.g., April 27, 2003) • Must pay a residential tax to a municipality as of January 1 in each year • Expectation • Surge in moving (on paper) in January 2003

16. Examples • Employees at a teppanyaki restaurant • Arrested in April 2004 • Asked many other employees to move their addresses to the restaurant’s address before a Minato-ward assembly election. • The manager of a retirement-home • Won a Moriya-city assembly election in 2007 • Found to live in another city

17. Model • Large data • More than 3000 municipalities • Monthly data (January 2001 – December 2004) • Four treatment effects estimated • LT effect | ET = 1 • LT effect | ET = 0 • ET effect | LT = 1 • ET effect | LT = 0

18. Model (cont.) • Base models • Differenced models

21. — treated, - - control

22. Conclusion • Theoretical implication • Mobilization as institutionally dependent • More comparative studies needed • Methodological implication • Validity of natural experiments, which allow us to estimate the overall effect of mobilization on multiple dependent variables