wfopen i:\panelboot\bpooldatabeta.wf1
equation eq1.ls(cx=f) y c x z 
!alpha=@coefs(1)
!beta=@coefs(2)
!gama=@coefs(3)
!n=1
!draws=999
vector(!draws) betavec=0
vector(!draws) tvec=0
for !n=1 to !draws
u.resample u_b
series yhat=!alpha+!beta*x+!gama*z+u_b
equation eqb.ls(cx=f) yhat c x z
betavec(!n)=(@coefs(2)-!beta)/@sqr(1/@sumsq(x-@mean(x)))
tvec(!n)=(@coefs(2)-!beta)/@stderrs(2)
next
wfsave i:\panelboot\bpooldatabeta.wf1
wfcreate(wf="tstatbeta") u 999
fetch(d=i:\panelboot\bpooldatabeta.wf1)  betavec tvec
series tser=0
series betaser=0
mtos(betavec,betaser)
mtos(tvec,tser)
betaser.hist
tser.hist
sort(d) tser
scalar lower=tser(950)
scalar upper=tser(50)
table(2,2) tvalue
tvalue.setwidth(1:2) 30
tvalue.setlines(a1:b2) +a
tvalue.setfillcolor(a1:b2) yellow
tvalue(1,1)="t-value lower (5%)"
tvalue(2,1)=lower
tvalue(1,2)="t-value upper (5%)"
tvalue(2,2)=upper
show tvalue
wfsave  i:\panelboot\tstatbeta.wf1