I was recently asked by a reader what the average applicant success rate is at each round in the case interview process.
This is a very good question and unfortunately the answer varies quite a bit.
The first step in the application process where cuts are made would be the Consulting Resume and Cover Letter Screen. This is by far where the biggest number of cuts are made. Its important to remember that MBB firms get an awful lot of resumes out of the blue -- but historically they have done the majority of recruiting out of the schools (under grad, MBA, JD, MD, PhD).
The cut at this level varies a lot. I can't speak to the PhD CV screen as I never screened those myself. When I was at McKinsey, the preference was to have alumni of a particular institution screen resumes and CV's from those institutions.
So Harvard MBA alumni would screen Harvard MBA resumes, PhD alumni would screen PhD CV's, etc... the idea was you wanted someone familiar with what's impressive on the resume and what's not.
The biggest factor on the resume / CV is the name of the school.
If a resume has Harvard MBA or Stanford MBA, it was like an automatic pass. McKinsey would interview anyone graduating from those programs for no other reason than they got admitted into those programs.
But if someone had an MBA from any other school, the screening would be a lot more strict.
The second most scrutinized item on the resume was usually some kind of numercial score - SAT, GRE, GMAT, LSAT, MCAT. Basically we were looking for people who were exceptionally smart especially in math and sciences.
Its not so much that consultant is that math driven (all the math I did while I was there was really adding, subtracting, multiple, and dividing... okay and a bunch of percentages), but the very structured, systematic, hyper logical, scientific method type thinking process that people with strong math scores tend to have, tend to handle that part of the job rather well.
After the resume and cover letter review stage we move on to the rounds of interviews.
Round 1 "pass rates" are the next most likely to vary. By the time you get to round 2 and 3, the numbers converge and are more consistent across recruiting sources. And Round 1 was usually done by alumni or people most familiar with the likely background of the candidate, the latter rounds would sometimes have more flexibility.
If I recall correctly, Round 1 pass rate was all over the place. You could interview 20 - 30 people who looked really good on paper, interview them in round 1, and take 2 people to round 2 (that would be on the low end).
If I had to give you a ball park and oversimplified estimate (and keep in mind this is a very, very, very rough ballpark), the "pass rate" might be
Round 1 - 10% - 20% at Round 1,
Round 2 - 10% - 30%
Round 3 - 20% - 50% for Round 3.
In general Round 1 pass rate is the lowest because either a candidate
1) totally lacks social skills (a deal killer) and we find out really quickly,
2) lacks practicality
or 3) can't do a case
Round 3 is a lot more of the same with a lot more data points (e.g, more interviewers) and is an opportunity for the firm to sell the candidate too.