Hello everybody, I have a question about designing a discrete choice experiment. My design contains: 2 unlabeled alternatives (Alt 1 and Alt 2) 5 attributes (x1, x2, x3, x4, x5) with three levels (0 = underachieved, 1 = sufficient, 2 = overachieved) 1 cost-attribute (x6) with four levels (0 = 0, 1 = 1%, 2 = 2%, 3 = 3%) Interaction effects between each of the 5 attributes (x1 – x5) and the cost attribute (x6) Restriction to avoid comparing Alt 1 with better attributes and lower costs with an Alt 2 with worse attributes and higher costs (and vice versa) Following the book “Marketing Research Methods in SAS” by Warren Kuhfeld, I created the following code: %mktruns(3 3 3 3 3 4, interact=x1*x6 x2*x6 x3*x6 x4*x6 x5*x6);
%mktex(3 3 3 3 3 4, seed = 200, n=144, interact=x1*x6 x2*x6 x3*x6 x4*x6 x5*x6);
%macro res;
g1 = (x[1,1:5])[+]; * Attributes in alt 1;
g2 = (x[2,1:5])[+]; * Attributes in alt 2;
bad = bad + (g1 > g2 & x[1,6] < x[2,6]); * Better attributes in 1 and lower price in 1;
bad = bad + (g2 > g1 & x[2,6] < x[1,6]); * Better attributes in 2 and lower price in 2;
%mend;
%mktlab(data=design, int=f1-f2)
proc print; run;
%choiceff(data=final, model=class(X1-X6), nsets=72, maxiter=20, seed=200, flags=f1-f2, options=relative, restrictions=res, resvars=X1-X6, beta=zero);
proc print; by set; id set; run;
%mktblock(data=best, nalts=2, nblocks=8, seed=200, maxiter=20); The final results are as follows: Finally, I still have the following questions: Is it correct to use the %mktex macro with n = 144 and the %choiceff macro with nsets = 72? Unfortunately, I don't understand exactly how the recommended size of the kandidate set relates to the size of the choice sets. Is my design able to estimate all parameters? Thank you so much!!
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