Private Equity puzzles, solved step by step
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019Five bidders each estimate an asset's value. Each estimate is the true value of 1,000 plus an error spread evenly between minus 200 and plus 200, and each bids its estimate. If you win the auction, what is your estimate on average, and what does that tell you about bidding?Large-cap buyout fund
Try it first
Given that you won, your estimate is on average:
Show the worked solution
About 1,133, so the winner overpays by about 133 on average. Each estimate is right on average, but the auction picks the highest of five. Five draws spread evenly between 800 and 1,200 sit on average at the sixths of the range, and the top one averages 800 plus five sixths of 400, about 1,133. To avoid overpaying, each bidder should bid below its own estimate, and by more as the number of bidders grows.
If every estimate is unbiased, how can the winner be wrong?
Picture five friends guessing the number of sweets in a jar. On average they are right, but the one who guesses highest is almost certainly too high. Each estimate is unbiased on its own, but the auction does not pick a random estimate; it picks the highest, and the highest of several noisy guesses is biased upwards. That is the {term('winner’s curse', 'The tendency for the winner of an auction, chosen because its estimate was highest, to have overestimated the value of what it bought.')}: winning is itself evidence that you overestimated.
Five estimates spread evenly from 800 to 1,200 sit on average at 867, 933, 1,000, 1,067 and 1,133, so the winning estimate averages about 133 above the true value of 1,000, and with ten bidders it averages about 1,164. Why does the top estimate average five sixths of the range?
Five points dropped at random on a line split it, on average, into six equal gaps. So the expected sorted estimates sit at one sixth, two sixths and so on up to five sixths of the way from 800 to 1,200: 867, 933, 1,000, 1,067 and 1,133. The top one is 400 x 5/6, or 333, above 800, which is 1,133. With n bidders the top estimate averages n over n plus 1 of the range, so ten bidders push it to about 1,164.
The relationshipL, H the lowest and highest possible estimates, 800 and 1,200 n the number of bidders, here 5 What it says in wordsThe highest of n evenly spread estimates sits, on average, n parts out of n plus 1 up the range.What does a disciplined bidder do with this?
Shade the bid. A bidder that wants to break even when it wins must bid as though its estimate is the highest of five, which in this setup means bidding about 133 below its estimate, and more in a crowded auction. That is the case for walking away from processes with many bidders and for building value on what the buyer can change rather than on a higher estimate of the same cash flows. Say the limits: real bidders have different information and different synergies, so not all of the gap is error, and a bidder with genuine private information is less exposed.
Where candidates lose it
The common answer is 1,000 because errors average out. They do across all bidders, but the question conditions on winning, and conditioning on being highest is the whole point.
The second loss is giving 1,133 and no implication. Close with what it means for behaviour: shade the bid, and shade it more as the field gets bigger.
What the interviewer asks next
- With two bidders, what does the winning estimate average?
- How much should each of five bidders shade its bid to break even on average when it wins?
- Why are sponsors with an operating plan less exposed to the winner's curse?
045A seller wants 100 upfront plus an earnout of 50 if year-2 EBITDA hits a target. You think the chance of hitting it is 40%. At a 12% discount rate, what is the earnout worth to you today, and what is the total price in value terms?Mid-market buyout fund
Try it first
What is the earnout worth to you today?
Show the worked solution
The earnout is worth about 15.9 to you, so the price in value terms is about 115.9. A 40% chance of 50 is 20 on average, payable in two years, and 20 / 1.12^2 is 15.9. The headline price is 150, but you are paying about 116 in value. A seller who thinks the chance is 80% values the same earnout at 31.9, which is why earnouts close price gaps.
How do you value a payment that may not happen?
A shopkeeper who offers a Rs 500 voucher to anyone who spends Rs 5,000 next month books its cost by how many customers she expects to claim it, not by the face value. An earnout is a contingent payment, so you value it as chance times amount, discounted for the wait: 0.4 x 50 / 1.12^2 is about 15.9. That number, not 50, is what the earnout adds to your price.
The relationshipp your estimate of the chance the target is hit, 40% EO the earnout payment, 50 r the discount rate, 12% t years until payment, 2 What it says in wordsAn earnout is worth the chance of paying it, times the amount, discounted to today.The same 50 earnout is worth 15.9 today to a buyer who puts the chance at 40% and 31.9 to a seller who puts it at 80%, so the buyer feels it is paying 115.9 while the seller feels it is receiving 131.9. Why does an earnout make a deal possible?
Because both sides can be right in their own terms. The seller, confident in the plan, values the package at about 132; the buyer, more cautious, values it at about 116; and the contract lets each side bet on its own view. If the target is hit, the buyer pays more but has a business that performed. If not, the buyer has paid 100 for a business that did not.
Say the risks. Earnouts are a common source of disputes: how EBITDA is defined, which costs the buyer loads onto the business after closing, and whether the seller's management stays to run it. A buyer controls the business that decides the payout, so the contract needs a tight EBITDA definition and agreed accounting policies.
Where candidates lose it
The common loss is counting the earnout at its face value of 50, which makes the price look like 150 and either overpays or kills the deal. The other is applying the probability but forgetting two years of waiting.
The second loss is treating the 40% as a fact. It is your estimate; the seller's is higher. Say that the gap between the two estimates is exactly what the earnout is for.
What the interviewer asks next
- What chance of hitting the target makes the earnout worth 25 to you?
- Would you rather the earnout be all-or-nothing or paid in proportion to EBITDA achieved, and why?
- How would you protect the seller from the buyer managing EBITDA down after closing?
069About 10% of acquisition targets have a real accounting problem. A quality-of-earnings review flags 90% of the problem cases, but it also flags 15% of clean ones. The review flags your target. What is the chance it really has a problem?Mid-market buyout fundPortfolio operations team
Try it first
Given a flag, how likely is a real problem?
Show the worked solution
About 40%. Picture 1,000 targets: 100 have a problem and the review flags 90 of them. Of the 900 clean targets, it wrongly flags 15%, which is 135. So 225 targets are flagged and only 90 of those are real problems, 90 divided by 225. A good test on a rare problem still throws up more false alarms than true ones.
Why is the answer not 90%?
Think of a smoke alarm that goes off for almost every real fire, but also for burnt toast. In a house where fires are rare and toast is daily, most alarms are toast. The 90% is the chance of a flag when there is a problem; the question asks the reverse, the chance of a problem when there is a flag, and the two differ because clean targets are far more common. Counting people instead of using percentages makes the reversal visible.
Of 1,000 targets, the review flags 90 of the 100 real problems and 135 of the 900 clean ones, so only 90 of the 225 flags, 40%, are real problems. The relationship0.10 the share of targets with a real problem 0.90 the chance the review flags a real problem 0.15 the chance the review flags a clean target What it says in wordsThe chance a flag is real is the true flags divided by all flags, true and false.What should a deal team do with a 40% flag?
Treat the flag as a reason to dig, not a reason to walk away. A flag lifts the chance of a problem from 10% to 40%, four times the starting level, but it still leaves the target more likely clean than not. A second, independent check changes the picture: if a forensic review with the same hit and false alarm rates also flags it, the chance rises to about 80%. The limit to state: that assumes the two reviews make independent mistakes, which two teams looking at the same ledgers may not.
Where candidates lose it
The common answer is 90%, mixing up the chance of a flag given a problem with the chance of a problem given a flag. Interviewers ask this precisely because the confusion is so natural.
The second slip is forgetting the false alarms entirely and answering 100% or near it. Write the four groups of 1,000 down, 90, 10, 135 and 765, before you compute anything.
What the interviewer asks next
- A second independent review also flags it. What is the chance now?
- How would the answer change if only 2% of targets had problems?
- Which matters more to a fund, the false alarm rate or the miss rate, and why?
