I was given an assighment to use a dataset contains quarterly unemployment rate data from 1957:q1-2013:q4.The question is to use AR(8) model to forecast unemploymen rate of change in 2012:q4-2013:q1.Here is my command,however it went wrong when I tried to use forvalue loop. And also the twoway tsline just have one actual line, there also should be a forecast line. Masters could you please give some suggestions on my command?

tsset quarter, quarterly

gen unrate1=ln(unrate)

gen deltaunrate=400*(ln(unrate)-ln(L.unrate))

capture drop deltaunrate_f

gen deltaunrate_f=.

forvalues t=`=tq(1957q1)'/`=tq(2012q4)' {

quietly {

regress deltaunrate L(1/8).deltaunrate L(1/8).if quarter>=tq(1957q1) & quarter<=`t'-1


Predict fitted

replace deltaunrate_f=fitted if quarter==`t'

drop fitted
}
}

twoway tsline deltaunrate deltaunrate_f if tin(1957q1,2012q4), legend(order(1 "actual unemployment rate" 2 "forecast unemployment rate")) aspectratio(0.5)
Array