#Sampling Distribution of OLS Slope Coefficient
#
n=100
nreps=20
beta=.3
alpha=0
x=1:n
plot(x,alpha+beta*x,ylab="y",col="blue")
betabig=NULL
for(iter in 1:nreps)
{
eps=10*rnorm(n)
y=alpha+beta*x+eps
fit=lsfit(x,y)
abline(fit)
betabig=c(betabig,fit$coefficient[2])
}
betabig=as.numeric(betabig)
title(main=paste("Sampling Distribution of Least Squares Line,",nreps,"replications
alpha=0, beta=.3, Ave beta hat =  ", round(mean(betabig),3),", SD beta hat =" , round(sqrt(var(betabig)),3),"
Least Squares Lines (Black), True Line (Blue)"))
#