None Utility too low

Question

Hi Guys,

I have recently ran an acbc study where my none-utility is very very low, which is raising red flags for me.

Pretty much every simulation I run has 100% of my products being chosen.

Even when I run the calibrated none set to a purchase intent of 5/5 my none barely increases - if at all.

Any price which is mildly below average has the ability to make a product selected over and above none.

It appears that this only occurs when I use the zero-centered diffs and not the raw utilities.

So two questions -

1) is this something that sounds familiar? That has a particular fix?
2) can I just manually increase the level of the none-utility to a level where current retention is reached and then just test my products from there?

Thanks for any help,

Dean

Comments

Hi Guys,

This issue only happens when I used the zero centered diffs, it is fine when I use the raw utilities.

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Zero-centered diffs should not  be used in market simulations...only raw utilities.  That's probably your issue.  

Zero-centered diffs are for cross-tabulating and showing average utilities for the sample or for subgroups of the sample.  Zero-centered diffs normalizes the utilities to have (roughly) equal scale per person for comparisons.