How many people can visit the best 1,000 tourist spots in their lifetime?

case question Guessestimation unusual case
New answer on Feb 14, 2023
5 Answers
asked on Feb 04, 2023

Dear valued coaches and community members,

I came across this unusual question recently while preparing for interviews and would like to share it with you, it goes like this:

“I have recently seen a brochure mentioning the top 1,000 places to visit in your lifetime, how many people do you think would be able to visit them all?”

Tackling this question was a little tricky without some the information from clarifying questions such as:

- How geographically dispersed are the 1,000 spots? This question would help in assuming how much time (in weeks let's say) it would take the average traveler to complete the trips.

- Accessibility of those places, which would affect travelers' capacity for the trip, for instance the top of Mount Everest is difficult to get to, and a Visa to North Korea would be out of the question for even -most of- the wealthiest of people.

How would you tackle such a question?

I would also be grateful if you had any thoughts on how I decided to tackle the question: 

Approach: Use the U.S as a population base (for simplicity), and filter down to the number of people capable of completing the trip across their lifetime.


1- Seperate Households into income/wealth brackets. I would take a minimum of Middle Income class and a net worth of around $250,000 as a qualification requirement for households, to make sure they could complete the multiple trips across time. My assumption would be that only 5% of households would fit into this bracket (I haven't checked the actual numbers in the spirit of simulating an interview scenario).

2- Estimate the average age and weeks per year of mobility for the average household member part of our reduced bracket. I assumed an average composition of a middle class household to be the following: 40 year old father, 35 year old mother, 10 year old daughter and 15 year old son. The average age of a household member would thus be 20 years old. 

In terms of mobility, I opted for the assumption that the average household would have 3 weeks of holidays per year during which they could travel.  

With a life expectancy of 80 years, an average age of 20 and 3 weeks of mobility per year, the average eligible household member would have 180 weeks of travel left in their lifetime.

From there, I would translate that into the amount of people in the U.S capable and then expand it to fit the global population. However, this last part is tricky as the U.S is one of the richest nations in terms of GDP per capita. This may be the biggest caveat in my approach.

What limitations would say this approach has?


Thank you for your time.





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Content Creator
replied on Feb 04, 2023
Ex-BCG Principal | 8+ years consulting experience in SEA | BCG top interviewer with ~5 years of interviewing experience


A very interesting estimation question indeed. 

Couple of thoughts from an interviewer's POV

  • You are right in that there are many variables and potential nuances in trying to size a question like this
  • As an interviewer, if I were to give this question to a candidate, I would expect the candidate to be able to:
    • Come up with a logical formula & structure
    • Take a reasoned stand on key assumptions (e.g. average dispersion between the spots; e.g. assume visa's are not a limitation or possible to get just a matter of time eventually (FYI there is a North Korea “Pyongyang marathon” you can run as part of an organized tour)
    • Most importantly, be able to understand where the greatest sensitivities are / most important variables
    • And for an interesting question like this, be able to discuss and argue on the practicality of the assumptions

My first instinctive reaction to this question is that being able to visit 1000 spots is really, really, difficult to do and that time rather than money is more of a barrier for people to achieve this. Just a small comment on your approach:

  • 180 weeks of mobility is 1260 days of travel. Even if you assume that it takes at least 2 days (1 day travel in, 1 day visit) for each destination, that means that only ~600 destinations can be reached - so even if you extrapolate that US number to the global number, none of them would hit the goal
  • If it takes longer to travel (assuming that it takes ~3 days for each spot (1 day travel in, 1 day on the actual spot/visit, 1 day travel out), that means that a person would have to travel for ~3000 days. That's ~8.2 years of travel, or 5-7 years of consecutive travel (assuming the flight out is to the next destination)
  • 5-8 years might sound possible for someone with alot of wealth, but as you have mentioned for the average house hold is probably mobile for just ~3 weeks a year

The above approach of course has several assumptions which are also sensitive. I would like to hit the top 1000 destinations in the world, but but just thinking of the practicality of it, it does appear to be really challenging :)

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Content Creator
replied on Feb 04, 2023
#1 McKinsey Coach by rating & recommendation rate

Hi there, 

I would note that first of all you'd need to clarify the question with the interviewer. 

Are we meant to understand the question as how many people will get to see ALL these places?


How many people put together will cumulatively create the necessarily overlap to have seen all these places?

Aside from this, your approach makes sense. :)



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Bahaa on Feb 04, 2023

Right! Thank you!

Victoria Christine
replied on Feb 14, 2023
1st&2nd session 33% off|Incoming BCG Consultant ME|President of the Consulting Club|Esade MBA|Offers from McKinsey & BCG

Dear Bahaa,

Your approach is great, but there are several limitations and assumptions that should be considered when you present it to someone. I will just share them with you so you use them as food for thought.

  1. Using the U.S. as a population base assumes that only people from the U.S. would be interested in visiting these places, which is not accurate.
  2. Limiting it to the top 5% of households in terms of net worth assumes that only wealthy people would be interested in visiting these places. However, people of all income levels may be interested in traveling to these destinations, and some may save up for years to be able to afford the trip.
  3. Assuming an average household composition and average age of 20 may not be accurate as people may have children at different ages and household compositions may vary.
  4. Assuming that people have 3 weeks of holidays per year may not be accurate as some people may have more or less vacation time depending on their job and personal circumstances.
  5. The assumption that people could travel for the rest of their lives may not be accurate as health issues and other circumstances may prevent some people from traveling later in life.
  6. Lastly, as you mentioned, extrapolating from the U.S. population to the global population may not be accurate as the U.S. has a higher GDP per capita and income level compared to many other countries.

Overall, it's important to acknowledge these assumptions and limitations when answering such a question and to be transparent about how you arrived at your estimate. But it seems that you already do this.:)

Best of luck with everything.

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Content Creator
replied on Feb 05, 2023
#1 Bain coach | >95% success rate | interviewer for 8+ years | mentor and coach for 7+ years

Hi Bahaa,

I think this is an interesting question that may be relevant for many people. I would be happy to share my thoughts on it:

  • In my opinion, your approach is unnecessarily complicated and requires a lot of assumptions. Given the only real restriction is money, it would be much simpler to estimate the costs of visiting the top 1,000 tourist spots and then determine the number of people who could afford such an expense over their lifetime. You could simply estimate the costs of a typical 1-/2-day-trip, multiply that figure by 1,000 (due to overlaps probably closer to 500-750), and arrive at the total costs.

If you would like a more detailed discussion on how to address your specific situation, please don't hesitate to contact me directly.



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Content Creator
replied on Feb 05, 2023
MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep

Hi Bahaa,

Honestly, I think you have grossly overcomplicated this. In my opinion (and if I were the interviewer) I'd want to see that you can critically think without taking some studied formulaic approach

You've tried to do classic market sizing, but it doesn't make sense here.

Here's what I would do.

1) Figure out $ needed to travel to 1,000 places. Quick “sizing” here. Have to estimate a “typical” trip (flight, accomodation, etc.) and multiply by 1,000

2) Figure out TIME needed to travel to 1,000 places. Exact same “sizing”

3) Allow for an “overlap” factor (you can likely see 3-5 places per trip, so you can divide the above by 3-5).

4) Estimate pop that has the required wealth for all of the costs (i.e. should be x % of their wealth)

5) Estimate population that has the required TIME for all of the trips (based on age)

Using the US is not the right approach. You should do developed versus developing/middle income world.

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Benjamin gave the best answer


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Content Creator
Ex-BCG Principal | 8+ years consulting experience in SEA | BCG top interviewer with ~5 years of interviewing experience
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