Principle
Organisations measure attrition as a rate and discuss it as a cost. Neither framing captures what actually matters, which is who left, why they left, and whether the reason they gave in their exit interview bore any relationship to the reason they actually left. Almost nobody knows the answer to the third question, because almost nobody has ever asked it in a way that could produce a truthful response.
Behaviour
A rep resigns. The exit interview is conducted by HR, in the final week, with a person who has just accepted a role elsewhere and has nothing to gain from candour and a reference to protect. The stated reason is career development, or compensation, or a growth opportunity. These reasons are recorded, aggregated into a quarterly report, and used to inform retention strategy.
The actual reason, in a substantial share of cases, is the manager. This is one of the most consistently observed findings in organisational research and one of the least likely to appear in exit interview data, because naming a manager as the reason for departure is professionally costly, achieves nothing for the departing employee, and risks a reference they may need.
The organisation therefore has attrition data that systematically excludes its most actionable cause. It invests in compensation benchmarking and career pathing, which address the stated reasons, and the attrition continues at the same rate under the same managers, who are never identified as the variable because the data collection method is structurally incapable of identifying them.
Almost nobody knows why people really left, because almost nobody has ever asked in a way that could produce a truthful answer.
Evidence
Segment voluntary departures by the manager the departing individual reported to, over a three-year window, normalised for team size. Attrition is rarely uniformly distributed. Where one manager's team shows a materially elevated voluntary departure rate over several years, that pattern is a finding regardless of what any exit interview recorded.
Cross-reference against performance. A manager losing weak performers is managing. A manager losing strong performers, particularly those who leave for lateral rather than upward moves, is producing regretted attrition, and the distinction is the entire diagnostic.
Conduct departure interviews six months after the individual has left, when they have no reference at stake and no ongoing relationship to protect. The candour differential between a week-one exit interview and a six-month follow-up conversation is substantial and consistent, and it is available to any organisation willing to run it. Almost none do.
Psychology
Nobody in the exit process is incentivised toward truth. The departing employee protects their reference and their reputation. HR is conducting a process that must be completed rather than an investigation that must be accurate. The manager, if they participate at all, has an obvious interest in an explanation that lies outside their control.
Senior leadership receives an aggregate report of stated reasons and treats it as data about causes. It is data about what people are willing to say on their way out of a building, which is a different thing entirely, and the gap between the two is precisely the information that would have been useful.
Commercial Risk
Commercial capability walks out of the door and the organisation records the wrong reason, which means it cannot stop it recurring. Regretted attrition among strong performers is the most expensive form of value destruction in a commercial organisation, and the population most likely to leave in the twelve months following an acquisition is precisely the population an acquirer most needs to retain.
An acquirer relying on the target's own attrition analysis is relying on a dataset that has never contained the operative variable. Segmenting departures by manager, and interviewing former employees who left more than six months ago, produces a materially different and considerably more actionable picture, and it is one of the cheapest analyses available in commercial diligence.
Investment Committee Note