Predictions for duration of government formation, Letta government

golder_letta.R

library(foreign)
library(survival)

dat <- read.dta("delay.dta")

dat$bargainingdays [which(dat$bargainingdays == 0)] <- .01

dat$post_legislative_parties <- dat$postelection * dat$legislative_parties
dat$post_polariz <- dat$postelection * dat$polarization
dat$post_positive <- dat$postelection * dat$positive_parl


mod.golder <- coxph(Surv(bargainingdays, ) ~ 
	postelection+legislative_parties+polarization+positive_parl+continuation+singleparty_majority,
	data=subset(dat,nonpartisan==0))

## Create new data for Letta govt.

effnum <- function(x) 1/sum((x/sum(x))^2)
senato.shares <- c(106,92,53,21,17,0,10,20)

newdata <- data.frame(bargainingdays = NA, postelection = 1,
	legislative_parties = effnum(senato.shares),
	polarization = mean(dat$polarization[which(dat$countryname == "Italy")]),
	positive_parl = 1,
	continuation = 0,
	singleparty_majority = 0)


curves <- survfit(mod.golder, newdata = newdata)
plot(curves)

the.day <- which.min(abs(curves$surv - 0.5))
the.day.upper <- which.min(abs(curves$upper - 0.5))
the.day.lower <- which.min(abs(curves$lower - 0.5))

abline(h=.5,lty=2)
abline(v=the.day,lty=2)