Hi Thomas,

the most important thing to do during a market sizing is to make reasonable hypotesis, easy steps and detail the steps as much as you can (make them deep) while maintaining an overall execution time within 10/20 mins max.

Said this, looking at your approach I find that your first assumption may be a bit hursh... you are basically saying that all the population in 1 yr bucket will have a child every year... so like saying people within 34 and 35 will have a child... All of them will have a child and nobody else will have. Unless I misunderstood your calculation

Maybe the number is also correct (idk), but for sure the hypotesis is not clear to me... I would have procced dividing the population into buckets (10 years span per bucket) and then defining some drivers as: Children yes/no (for example below 15 and over 70 I sould say no), then Likelyhood ( from 20 to 30 maybe 20%, from 30 to 40 maybe 30%, from 40 to 50 maybe 20% ...) thenyou can add your filter (1st/ 2nd child)... and so on

But I would have been much more granular while making the hypotesis and explaining them to the interviewer. Remember the number is important, but is nothing without a clear, reasonbable and understandable explanation

Hope this can help

I like your approach! It is pragmatic, easy to follow, and allows for a clear discussion of the different underlying drivers.

Cheers, Sidi

(edited)

Hi there,

Providing some market sizing thinking for anyone revisiting this Q&A:

Remember that there's rarely a "best" answer with market sizing. What's important is that you break down the problem the way it makes sense to you. Importantly, break it down so that the assumptions you make are the ones you're most comfortable in.

For example, do you know all the major brands? Great go with that. Do you understand all the segments of that country's population (either age or wealth or job breakdown)? Go with that. Do you know the total market size of the tourism (or hotel) industry? Then break it down that way.

Some tips:

1. Just like in a case, make sure you understand the question - what are you really being asked to calculate
2. Decide whether a top-down or bottom-up approach is best
3. Figure out what you know you know, and what you know you don't know, but could estimate
   1. This helps you determine how to split out buckets
4. Stay flexible - you can start with a "high-level" market sizing, but gauge your interviewers reaction....if it looks like they want you to do more...then go along level deeper in terms of your splits

Clara

(edited)

Somethings to be considered, just sharing, thanks:

1. should be strollers for new babies, and for existing babies' replacement (can add this at the end with a %)

2. % use strollers, % not use

3. 1st baby can buy new & second hand, 2nd baby can also buy new & second hand

4. the babies are from low income, middle income and rich families, so the average price can be segmented further