Let's use a top down approach. We can start with total bears population, segment according to the type of bears, and then…

Just kidding here. This is a very specific question and providing you with an answer won't help you with similar type of problems. It's best if you give it a try yourself.

In any case, here's my answer. We need to consider polar bear populated area * polar bear density per area.

You'll need to have some basic geography numbers in your head to do this. For example, I know that Portuguese population density is 100 people per km2 (and there are 10million people in the country). So that's 10m/100=100.000 km2 in the country. 

So let's assume the relevant polar bear populated area is the equivalent to 20x Portugal (that should be close to Greenland), and that there's a polar bear per each 50kms. I know that a lion needs several kms. So a predator in a cold area will need much much more.

So that means the area is 100.000 * 20 = 2m km2
And the population density is 1/50. 

So polar bear population is 2,000,000 / 50 = 40.000 bears.

Does this sound reasonable? We hear that it is an endangered species, so I feel comfortable with this number (for example 4 million would not make sense for an endangered species).

Note: there are 20-30,000 polar bears in the world.

Hi Dennis,

Why don't you try to solve this yourself and then we can review!

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

Here's some practice: https://www.preplounge.com/en/management-consulting-cases/brain-teaser/intermediate/taxis-in-manhattan-market-sizing-229

(editiert)

They are being wiped out by climate change and human activity. How to calculate this & how relevant is this question in interview anyway? I will be keen to understand the calculations too.