I am trying to simulate second difference using Zelig, here is my code:

——————————————————–

data(turnout)

# estimation

z.out <- zelig(vote ~ race*age + educate + income,

model = “logit”, data = turnout)

summary(z.out)

# first difference

x.low <- setx(z.out, educate = 12)

x.high <- setx(z.out, educate = 16)

s.out <- sim(z.out, x = x.low, x1 = x.high)

s.low <- sim(z.out, x=x.low)

s.high <- sim(z.out, x=x.high)

dif <- (s.high$qi$ev – s.low$qi$ev)

# second difference

x.low.low <- setx(z.out, educate = 12, age = 20)

x.low.high <- setx(z.out, educate = 12, age = 30)

x.high.low <- setx(z.out, educate = 16, age = 20)

x.high.high <- setx(z.out, educate = 16, age = 30)

s1 <- sim(z.out, x = x.low.low, x1 = x.low.high)

s2 <- sim(z.out, x = x.high.low, x1 = x.high.high)

did1 <- s1$qi$fd – s2$qi$fd

# or equivalent

s3 <- sim(z.out, x = x.low.low, x1 = x.high.low)

s4 <- sim(z.out, x = x.low.high, x1 = x.high.high)

did2 <- s3$qi$fd – s4$qi$fd

———————————————————

It would be great if Zelig can do this directly though.

*Related*

To

**leave a comment** for the author, please follow the link and comment on their blog:

** Shige's Research Blog**.

R-bloggers.com offers

**daily e-mail updates** about

R news and

tutorials on topics such as:

Data science,

Big Data, R jobs, visualization (

ggplot2,

Boxplots,

maps,

animation), programming (

RStudio,

Sweave,

LaTeX,

SQL,

Eclipse,

git,

hadoop,

Web Scraping) statistics (

regression,

PCA,

time series,

trading) and more...

If you got this far, why not

__subscribe for updates__ from the site? Choose your flavor:

e-mail,

twitter,

RSS, or

facebook...