Resolved: Help! There might be an error in Customer Analytics course. Possible wrong chosen coefficient.

Hi Jesus,  thanks for reaching out and for your question! The idea here is that though we're examining cross brand 4, our own brand remains brand 5, this is why we still use the same coefficient. When examining the price elasticity of a brand (or indeed with most of marketing analysis) we're interested in our own brand and that's the perspective we take a look at. In our case the beta coefficient is the coefficient for the Brand variable, and not for the segment variable. Thus, it does not change across segments, it would change for a different brand. Hope this helps!   Best,  The 365 Team

Hello Eli,
thanks for your answer. I understand that I have to take the coefficient for Brand 5, and I agree with that. But I still don't understand 1 fact and I have a doubt about 1 idea:
Analyzing directly the exercise provided in the lecture, we have:
- Fact: We are selecting Training Data from Segment “Well-Off”, then and naturally we obtain the coefficients for Segment “Well-Off”, BUT we don’t use them, instead we still use the old beta5 = -1.09, the coefficient for the whole Brand and no particular Segment filtered, then Why do we calculate the coefficients for Segment “Well-Off”?
- Idea: Maybe I´m wrong, but I understand that we are calculating the coefficients based on Training Data exclusively from Segment “Well-Off” to obtain the coefficients for all Brands and, of course, exclusively for Segment “Well-Off”, as you do in the lecture, and so, to use the proper coefficient for Brand 5 and Segment “Well-Off” as you don’t do in the lecture. I think the selected coefficient must change due to the change in Training Data to fit the model, being selected the coefficient for Brand 5, but the one that fits the data, I mean, for the Segment “Well-Off” = -0.44.
The picture at the link below was taken directly from the example provided on your lecture, nothing was changed except I added one last line to see the actual value of beta5:

https://drive.google.com/file/d/1x0lKFLZjtZGOXjz9zZbqm9bGjjZXoktq/view

Hi Jesus,
the reason that we use the coefficient for brand 5 is that the coefficient is determined by the brand and not the customer segment.
Hope this helps!
Best,
365 Eli

Hi Eli,
I´m sorry, but that was your answer since the first time I submitted the first question, but the second question is different and remains without answer: I agree using the coefficient for brand 5, but the one you calculated later in you example, I mean the one with the data from segment ´Well-off´:
If you will use the coefficient for brand 5 with value -1.09, then and please tell me ¿Why do you calculate the coefficient for brand 5 and SEGMENT ´Well-off´ (with value -0.44) and NOT going to use it? I mean, ¿Why do you calculated the coefficients on that dataframe? You calculate them in your example but you NEVER use them.
Please check the picture below:

Expanding my clarification:
Maybe I´m not explaining myself well.
I decided to take a screenshot right from the lecture, so you can see it is taken right from the lecture and what are the bunch of coefficients that were calculated and not used anywhere, any of them (Coefficients for Segment ´Well-Off´). I want to know why those coefficients were calculated and not used. What´s its purpose in the lecture?:

Hi Eli,
Thank you for telling me this, I was confused but I can see now the purpose of the table.
Best,
Jesús.