How to solve this estimation case: "How many trees are there in New York City"

Case estimation Market sizing
New answer on Nov 21, 2019
3 Answers
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Jessie asked on Nov 18, 2019

Hi everyone,

This is an interesting estimation case I met several days ago. I am wondering how to solve it. My initial thoughts was to firstly segment the areas where trees are planted, open area (mainly streets in my assumption) and closed areas.

For open areas, I may estimate how many streets are there in new york, their average length, and the distance between each tree, in order to estimate the total trees by the streets.

For closed areas, I will continue to segment them into major public areas that contain trees, like schools, hospitals, parks, and assign an average number of trees to each segment.

I think it's not a case that is meant to make us akaward, as long as we can provide a convincing framework. So I am not sure whether my framework is MECE, and I am looking forward to hear from everybody here.

Thanks!

Best,

Jessie

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Vlad
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replied on Nov 18, 2019
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School

Hi,

It's easier to:

  1. Segment New York into blocks using the number of streets and avenues.
  2. Calculate separately the area of the parks
  3. Assume a certain number of trees per block and separately for the parks
  4. Multiply and sum up

Best

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Anonymous A replied on Nov 18, 2019

Hi Jessie,

Rightly said, this is an interesting problem. My approach would have been as below:

Step 1: Estimate the total area of New York City

Step 2: Divide that area into three parts as per tree coverage (high, low and medium density coverage of trees and substantiate with exampls high --> central park, low --> times square etc)

Step 3: Estimate the area for each of the three buckets

Step 4: Estimate number of trees per sq. mile for three categories

Step 5: Use numbers from Step 3 and Step 4 to arrive at number of trees

Let me know your throughts on the above approach

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Udayan
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replied on Nov 21, 2019
Top rated MBB coach with many offers /Ex McKinsey EM in New York /6 years McKinsey recruiting experience/Real cases

One thing to take into account specifically for NYC is Central Park! Make sure you account for both it's size and density of trees in your answer.

Also note that Brooklyn has more parks than Manhattan so be specific about what you boroughs classify as NYC

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Vlad gave the best answer

Vlad

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McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
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