When is it appropriate to directly ask "WHY" in a case interview?

Question

When doing cases, I was trained that I shouldn't ask open ended questions, and that it is better to brainstorm possible reasons and test with interviewer.

When I was reviewing Victor Cheng's LOMS program, he mentioned it is important to ask WHY questions. I have provided to examples of how he asked the question in the sample case as below.

My question is: (1) How to ask the WHY - is it fine to ask WHY, or it's always better to bring out some hypo? (2) When is asking “WHY” appropriate? Does it depend on the “Depth” that you go into the root cause? (e.g. for higher level such as “quantity dropped”, it definitely doesn't make sens to ask WHY.)

Example 1:

Interviewer: The competitors usually do a production run, it takes them about 90 days to complete a run.

Candidate: That’s interesting. Why is there such a big difference between the two? Our client’s doing it in three days and the competitors are doing in 90 days.

Example 2:

Candidate: We’re buying it from the same place, we can’t change where we buy it from, and yet our competitors are getting a lower price. Do we have any data as to why the competitors are able to get a lower price? Are they perhaps buying in larger volume, getting some sort of volume discount, because I know they are bigger. Do we have any data on that?

Thanks!

Answer 1

Hi there,

The way I used to do it in case interviews was along the lines of “Interesting difference in [customer behaviour]. I wonder why that is the case. My guess / hypothesis is it's because of XYZ. Do we have any data on that?”.

To specifically answer your question: I would avoid simply asking “Why?” and try to offer a hypothesis or at least a good reason for asking.

If I think about real-life client situations, it is not too dissimilar. In your first client meeting, even senior partners would mainly listen, ofer hypothesis, ask clarifying questions and occasionally asked some well-placed whys.

Hope this is helpful!
Ariadna

Answer 2

Hi there,

Simply asking why is not getting you very far. This is too broad of a question to ask the interviewer. Rather, you need to probe more specifically what you want to know (what, why, how).

When listening to LOMS keep in mind that VC was at McKinsey before the turn of the century and interviews at MBB etc have evolved a bit since then…

Cheers,

Florian