@ program to simulate the range of a unit root series over the period 1945-1996 @

n=208;                  @ number of quarter that elapse @
y0=60;                  @ starting level of macropid    @
a=0;
b=1;                    @ autoregressive coefficient    @
sig=1.82;               @ standard error of estimate    @
t=seqa(1,1,n);
repls=0;
let stackr[1,2] = . . ;

do while repls < 5000;

	u=sqrt(1.82)*rndn(n,1);
	y = recserar(a+u,y0,b);

	big=maxc(y);
	sml=minc(y);

	stackr=stackr|(big~sml);
	repls=repls+1;

endo;


stackr=trimr(stackr,1,0);

e = (stackr[.,1] .gt 80) .or (stackr[.,2] .lt 20);

let v = 1 0;
out8020 = code(e,v);

e = (stackr[.,1] .lt 70) .and (stackr[.,2] .gt 49);

let v = 1 0;
out7049 = code(e,v);

print "percentage of " repls " replications in which y went outside {20%,80%} bounds:";
print meanc(out8020);
print;
print "percentage of " repls " replications in which y stayed inside {49%,70%} bounds:";
print meanc(out7049);