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Market size: How many babies are born every year? (Healthcare consulting firm)

market size marketsizing
New answer on Oct 25, 2023
6 Answers
Anonymous A asked on Oct 18, 2023

Hi all, 

I was wondering if I am applying to a consulting firm within the health care sector and they ask me "How many babies are born every year?", could I give the approach:

  • US population: 320M
  • Life expectation: 80y
  • Population equally spread for every age -> 0-1 years old: 320M/80 = 4M babies per year

Or is there another approach of how many babies are born in each hospital every year times the number of hospitals in the country?

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Content Creator
replied on Oct 25, 2023
FREE 15MIN CONSULTATION | #1 Strategy& / OW coach | >70 5* reviews |90% offers ⇨ | MENA, DE, UK

Hello! When answering the question about the number of babies born every year in the context of the healthcare sector, it's important to consider the specific focus of the consulting firm and the information available. While your approach of using the overall population and life expectancy to estimate the number of babies born per year is a reasonable starting point, it may not provide the most accurate answer in this case.

To provide a more precise estimate, it would be beneficial to gather data specifically related to the healthcare sector and childbirth statistics. This could include factors such as the birth rate per 1,000 people, the average number of births per hospital, and the number of hospitals in the country. By combining these data points, you can arrive at a more accurate estimate of the number of babies born each year within the healthcare sector.

It's important to demonstrate your ability to think critically and gather relevant information to arrive at a well-informed answer. If you have access to additional data or can make reasonable assumptions based on industry knowledge, be sure to incorporate those into your analysis. This will showcase your analytical skills and attention to detail, which are highly valued in the consulting field.

Remember, the key is to provide a logical and data-driven approach that aligns with the specific context of the question. If you have any further questions or need more guidance, feel free to ask!

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replied on Oct 18, 2023
Bain | Roland Berger | EY-Parthenon | Mentoring Approach | 30% off first 10 sessions in May| Market Sizing | DARDEN MBA

While your approach is ok , it doesn't get you an offer.

The best approach really depends on what you are trying to do here. If you want to do it “quick and dirty” or are just checking a number, it's fine.

If this is a number that has some relevance (i.e., being closer to the exact number has added value), then you need add a bit of nuance, because in reality you are using an oversimplification.

So a few of things to consider: 

  • Is the population growing or being stable? 
  • Is this from naturage growth, immigration, or population aging?

This means that for countries like Japan where people are getting older but don't have a lot of immigration, you would be overestimating. For countries like France or the US (which have aging population, but also population growth), you'd be probably right, or little adjustment would be necessary. For countries with high population growth, and very young population pyramids, like Algeria, your approach would be grossly underestimating the number of babies.

Regarding the best approach? In my opinion, for this it would be to consider the Average number of children per woman (the easiest way to implement this is as an adjustment factor to your estimate; a more “accurate” way would be to calculate number of woman in fertile age, and then use this to perform the estimation).

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Content Creator
updated an answer on Oct 19, 2023
#1 BCG coach | MBB | Tier 2 | Digital, Tech, Platinion | 100% personal success rate (8/8) | 95% candidate success rate

Hi there,

Yes and no!

Ok, so you have the right idea here in terms of top down - it's definitely a top down problem.

However, it's too simple.

Generally, I don't advise complexity for the sake of it, but we do need a bit more. 

For example, you could segment by child-birthing age. You could also reference the population pryamid and that country's growth rate (based on your own knowledge)

I would not do bottom up here (Number of hospitals times # of babies per hospital)

==================MARKET SIZING ADVICE===========

Additional practice (with video solutions!):


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


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Content Creator
replied on Oct 18, 2023
#1 rated MBB & McKinsey Coach

Hi there!

Your approach is a top-down one, it's quite simple, to the point and it works. 

Alternatively, yes, you can go for a bottom-up approach where you look at the number of hospitals and the number of babies born in each of these hospitals on average. 

The challenge with this later approach is that you now need to do two further estimations i.e., you need to figure out how many hospitals are in the country and then figure out the average number of births for each. 

If I were in the actual interview, I'd basically go for the first approach (the top-down one) to get to the answer quickly, then in the interpretation of the answer I'd tell the interviewer that I have this other approach (the bottom-up one) that I could use to validate my top-down approach (without actually going ahead and doing it). 




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Content Creator
replied on Oct 18, 2023
ex Jr. Partner McKinsey |Senior Interviewer| Real Feedback & Free Homework between sessions|Harvard Coach|10+ Experience

Agree with top-down approach, you might challenge the assumption of even distribution but fair enough. Warm regards, Frederic 

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replied on Oct 18, 2023
FREE INTRO I exMcKinsey EM I exKearney consultant I High Success Rate I Official Coach for HEC (160 coachees in 2022/23)


I think that a top down approach as you do is the right one. You need to also express that your approach is right if population is constant and life expectancy is stable, if not you need to add to this number the yearly population growth adjusted with life expectancy growth.

Global formula would be then : 4M + [X% population growth]*[Total population] - [life expectancy growth in years]*4M



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Raj gave the best answer


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