Issue with model saving in Serde not keeping media prior type

[twolf89]

• Meridian version: 1.7.0
• Python version
• Issue: paid_media_prior_type='contribution' is not preserved through serde save/load — when checking after loading, the posterior contains roi_m instead of contribution_m which the model was set up with.

[dattatreyam23]

Hi @twolf89 ,

Thank you for reaching out!

We investigated the behavior, but we have unfortunately been unable to reproduce the issue on our end. Could you please provide a few more details about your setup or the exact steps you are taking? For your reference, you can view the script and parameters we used in our reproduction attempt here: https://gist.github.com/andyl7an/455b74e01ec7244e333a41bd2f047f5e. Let us know if your configuration differs from this.

During our testing, we did notice that both versions generated the following serialization warning:
Paid media prior type is unspecified. Resolving to default: PAID_MEDIA_PRIOR_TYPE_UNSPECIFIED.

It appears this is caused by a deprecated combined parameter. Please rest assured that this warning is completely harmless and should not impact your results. However, we understand that it can be confusing, so we are going to submit a change to suppress this warning in a future update.

Hope this helps. Feel free to reach out to us with any further queries regarding Meridian.

Thank you,

Google Meridian Support Team