Complete Case Interview Preparation by Marc Cosentino

The Interview

• Have three stories for each answer
• Memorize bullet points - makes your answer focused, linear, and of an appropriate length
• Your voice should carry sincerity and enthusiasm
• They might test your quantitative skills
• Students receive job offers in consulting for four reasons:
  • They are able to convince the interviewer that they are committed to consulting and know what they’re getting into (e.g., type of work, lifestyle, travel)
  • They can demonstrate success-oriented behavior
  • They exhibit good analytical skills when answering case questions - drawing conclusions from data
  • They are able to articulate their thoughts, create a positive presence, and defend themselves without being defensive

Case Questions

• The business of consulting really is the renting of brains, packaged and delivered with an engaging and confident personality.
• Firms look to see whether you have that “rip through it” look in your eyes. It’s called confidence.
• One of the best ways to learn how to answer a case is to write your own case. You are basically re-engineering the process. You need to think of a structure, plus the answers to all the questions that an interviewer would ask.
• They all look for the same four things: structure of thought, confidence level, communication skills, and going beyond the expected answer - that is creativity
• The interviewer is more interested in your logic and thought process than whether your assumptions are spot-on
  • If you are still concerned, you can always say, ‘I’m not that familiar with this market, so if my assumptions are off, please correct me.” Ninety percent of the time, the interviewer will tell you not to worry about it. However, everything you say has the potential to be questioned - so be ready to defend your assumptions, as they should be based on some type of logic.
• Key numbers to memorize:
  • US population is 320 million
  • Life expectancy of an American is 80 years
  • Even distribution between the ages; that’s is, there is same number of 2-year olds as 72-year-olds. We know that this is not true, but in a case like this, it’s fine to assume; thus 4 million people per age group. There are 80 million per generation
  • There are 100 million US households
• Example - How many cups of coffee, or coffee drunks, are consumed in the US on a typical day?
  • Make assumptions and break the population down by generation
  • Determine the number of coffee drinkers in each generation
  • You may want to draw a chart to show how well organized you are and how logically you think. It also makes it easier for the interviewer to follow your thought process
  • Estimate the number of light drinkers, medium drinkers, and heavy drinkers. Assign an average number of cups per day.
  • Review the final answer to see if that number makes sense. If it doesn’t tell the interviewer that you think that number seems high and pick a new number that seems more reasonable. You don’t have to go back through the process again, they know your process. It was just that one of your assumptions was off.
• Whenever you get a worldwide market-sizing case, don’t start with 8 billion people and whittle your way down. Instead, pick one country, make assumptions, and then extrapolate out.
• The most common math you’ll see in a case interview are percentages, ROI, breakevens, weighted averages, net present value, and multiplication and division with lots of zeros
• Whenever you do a calculation, ask yourself, “Does this number make sense?”