choice-metrics.com

Dear Dr Bilemer,
I'm using Ngene to generate the SP survey design first time, and I created a Bayesian efficent model to complete the design. In the end, I found the Bayesian mean D-error was larger than fixed D-error. The results are as follows.

Fixed Bayesian mean
D error 0.186766 0.355442
A error 6.613701 18.16263
B estimate 77.2706 0.38612
S estimate 359.009045 3525.984452
My question is that I found some papers said the Bayesian efficient esimation is better than D-efficient method, but why my result is opposite?

Thank you so much for your help and time.

There is no such thing as "Bayesian efficient model" or "Bayesian efficient estimation". An experimental design is Bayesian efficient if the design has a low Bayesian D-error.

A Bayesian D-error is the average D-error over a range of draws from a distribution of prior values instead of a specific fixed prior value. This average D-error is expected to be larger than the D-error when optimising only for a fixed value.

Using a Bayesian efficient design is usually considered better than a local D-efficient design because it is more robust to prior misspecification.

Michiel