gistfile1.txt

# DATA PREPROCESSING
foo <- read.csv("https://tinyurl.com/y2zt2hyc")
foo <- foo[, c(6:8, 11:16, 99, 50, 114, 49, 63, 136, 109, 126, 48, 160, 142, 10)]
foo <- foo[c(-19, -47), ]
which(is.na(foo) == TRUE)
head(foo)

# What is the 3 digit country code associated with the first row of the data set?
foo$clust2[1]
foo$yrbeg[1]

# Treatment is peacekeeping (2)
# Outcome is peacebuilding success (1)
# Confounder is any of 3, 4, or 5
# SUTVA could be violated, since interventions in one country may affect the 
# outcomes of another (most likely neighboring) country. Furthermore,
# countries do not receive exactly the same treatment, since peacekeeping
# mission vary along several dimensions.


# DATA ANALYSIS
# How many treated units?
sum(foo$untype4)

# How many control units?
length(foo$untype4) - sum(foo$untype4)




# P-SCORE MATCHING
library(Matching)

# Compute the propensity scores
lm.prop <- glm(untype4 ~ wartype + logcost + wardur + factnum + factnum2 + trnsfcap + treaty + 
             develop + exp + decade, data=foo, family="binomial")
X <- lm.prop$fitted.values

# Do the matching
matchout.prop <- Match(Y = foo$pbs2s3, Tr=foo$untype4, X=X)

# Check the balance
mb.out <- MatchBalance(untype4 ~ wartype + logcost + wardur + factnum + factnum2 + trnsfcap + treaty + 
          develop + exp + decade, data=foo, match.out = matchout.prop, nboots=1000)

mb.out$AMsmallestVarName
mb.out$AMsmallest.p.value


# MULTIVARIATE MATCHING
attach(foo)
X <- cbind(wartype, logcost, wardur, factnum, factnum2, trnsfcap, treaty, develop, exp, decade)
detach(foo)

matchout <- Match(Y = foo$pbs2s3, Tr=foo$untype4, X=X)
mb.out2 <- MatchBalance(untype4 ~ wartype + logcost + wardur + factnum + factnum2 + trnsfcap + treaty + 
               develop + exp + decade, data=foo, match.out = matchout, nboots=1000)

mb.out2$AMsmallestVarName
mb.out2$AMsmallest.p.value

# Risk of confounding addressed: NO

# GENETIC MATCHING
genout <- GenMatch(X = X, Tr = foo$untype4)
matchout.gen <- Match(X = X, Tr = foo$untype4, Y = foo$pbs2s3, Weight.matrix=genout)
mb.out3 <- MatchBalance(untype4 ~ wartype + logcost + wardur + factnum + factnum2 + trnsfcap + treaty + 
               develop + exp + decade, data=foo, match.out = matchout.gen, nboots=1000)
mb.out3$AMsmallestVarName
mb.out3$AMsmallest.p.value