http://spssx-discussion.165.s1.nabble.com/Simulation-with-SPSS-tp2856363p5503673.html
The following syntax will generate data which meets your specification of a non-significant paired t-test. Write back if you have any questions about the syntax.
*Generate data for a pair t-test.
set seed 65923454.
new file.
inp pro.
compute subject=-99.
compute time = -99.
compute x1 = -99.
compute x2 = -99.
compute e1 = -99.
compute e2 = -99.
compute sigma = 1.
compute rho = 0.50.
compute a11 = 1.
compute a21 = rho.
compute a22 = sqrt(1 - rho**2).
leave subject to a22.
loop subject= 1 to 500.
compute x1 = rv.normal(0,1).
compute x2 = rv.normal(0,1).
compute e1 = sigma * a11*x1.
compute e2 = sigma * (a21*x1 + a22*x2).
loop time = 1 to 2.
compute y = 1.5 + 0.0*(time=1) + e1*(time=1) + e2*(time=2).
end case.
end loop.
end loop.
end file.
end inp pro.
exe.
delete variables x1 x2 sigma rho a11 a21 a22 e1 e2.
*Restrcture dataset from long to wide.
SORT CASES BY subject time.
CASESTOVARS
/ID=subject
/INDEX=time
/GROUPBY=VARIABLE.
*Run paired t-test.
T-TEST PAIRS=y.1.00 WITH y.2.00 (PAIRED)
/CRITERIA=CI(.9500)
/MISSING=ANALYSIS.