############################## # # Script: assignment07a.R # Answers to the seventh # homework assignment # ############################## # Preamble library(RFS) ##### Part I: GDP per capita # Read in data gdp <- read.csv("http://courses.kvasaheim.com/pols6123/data/gdpcap.csv") attach(gdp) # Model model.a <- lm( log(gdpcap) ~ hig + govt) summary(model.a) model <- lm( log(gdpcap) ~ hig * govt) summary(model) # Predict newHIG <- seq(1,10,length=1000) prDEM <- exp( predict(model, newdata=data.frame(hig=newHIG, govt="Democracy") ) ) prANO <- exp( predict(model, newdata=data.frame(hig=newHIG, govt="Anocracy") ) ) prAUT <- exp( predict(model, newdata=data.frame(hig=newHIG, govt="Autocracy") ) ) # Graph png("gdpgraph.png",height=6,width=6,units="in",res=600) par(cex=0.8, cex.lab=0.8,cex.axis=0.8) par(mar=c(5,5,1,1)) plot(hig,gdpcap, las=1, xlab="Level of Honesty in Government",ylab="GDP per Capita ($)\n") lines(newHIG,prDEM, lwd=2, col=3) lines(newHIG,prANO, lwd=2, col=4) lines(newHIG,prAUT, lwd=2, col=2) legend("topleft", col=c(3,4,2),lwd=2,bty="n", c("Democracy","Anocracy","Autocracy")) dev.off() ##### Part II: SSM Ballot Measures # Read in data ssm <- read.csv("http://courses.kvasaheim.com/pols6123/data/ssm2.csv") attach(ssm) # Model model.a <- lm( logit(propFavor) ~ south + povertyRate) summary(model.a) model.g <- lm( logit(propFavor) ~ south * povertyRate) summary(model.g) # Predict newPoverty <- seq(1,100,length=1000) prS <- logistic( predict(model.g, newdata=data.frame(povertyRate=newPoverty, south=1) ) ) prN <- logistic( predict(model.g, newdata=data.frame(povertyRate=newPoverty, south=0) ) ) # Graph png("povgraph.png",height=6,width=6,units="in",res=600) par(cex=0.8, cex.lab=0.8,cex.axis=0.8) par(mar=c(5,5,1,1)) plot(povertyRate,propFavor, las=1, xlab="Poverty Rate (%)", ylab="Proportion Vote in Favor", pch=16,col=4,xlim=c(0,25),ylim=c(0.4,1)) points(povertyRate[south==1],propFavor[south==1], pch=16,col=2) lines(newPoverty,prS, lwd=2, col=2) lines(newPoverty,prN, lwd=2, col=4) legend("topleft", col=c(4,2),lwd=2,bty="n",pch=16, c("Non-Southern State","Southern State")) dev.off() ##### Part III: GDP per capita Extra Credit # Graph png("gdpgraph-xc.png",height=6,width=6,units="in",res=600) par(cex=0.8, cex.lab=0.8,cex.axis=0.8) par(mar=c(5,5,1,1)) plot(hig,gdpcap, las=1, xlab="Level of Honesty in Government",ylab="GDP per Capita ($)\n", pch=18,col=2) points(hig[govt=="Democracy"],gdpcap[govt=="Democracy"], pch=18,col=3) points(hig[govt=="Anocracy"],gdpcap[govt=="Anocracy"], pch=18,col=4) lines(newHIG,prDEM, lwd=2, col=3) lines(newHIG,prANO, lwd=2, col=4) lines(newHIG,prAUT, lwd=2, col=2) legend("topleft", inset=c(0.025,0),col=c(3,4,2),lwd=2,bty="n", c("Democracy","Anocracy","Autocracy"),pch=18) dev.off()