[Limdep Nlogit List] To execute the complete combinatorial test

[aoki keiko]

Dear all,

Happy new year everyone!

I want to execute the complete combinatorial test (Poe et al., 2005) 
between WTPs in groups A and B estimated by the RPL model. Also, I have 
estimated the CI by Krinsky and Robb methods.

Based on the comments of this mailing list in “Comparing WTP values (Mar 
8, 2010),” I have code this test, but it doesn’t work. Where is the wrong?

My CODE: after the estimation by the RPL model

Wald; ? for Group A.

Labels=p, s, t;

Parameters=b;

Covariance=varb;

Fn(1)=wtp_sa=(s)/(p);

K&R;pts=1000$

crea; x=wtp_sa ; y = wtp_sb $

calc; m = 1000; l = 1000 ; ixy=0 ; nd0 = 0 $

matrix ; ones = init(m,1,1)$

matr; my = y $

crea; vd = 0 $

sample ; 1 - m $

proc $

calc; ixy=ixy+1 ; xi = x(ixy) $

matrix ; md = xi*ones - my $

crea; vd = md $

crea; vd = vd < 0 $

calc; nd0 = nd0 + sum(vd) $

endproc;

exec $

Could you help me?

Thank you for your time in advance

Keiko