Among the many studies linking women’s leadership to corporate performance, one stands out for the sheer size of the number it produced and the rigour of the method behind it. In 2019, S&P Global — one of the world’s most influential financial-data companies — published research finding that firms which appointed women as chief financial officers generated $1.8 trillion in additional profit in the two years following those appointments. It is a figure large enough to invite scepticism, which is exactly why the details of how it was reached matter.
The study behind the headline
The research, titled When Women Lead, Firms Win, was produced by S&P Global Market Intelligence’s Quantamental Research team and released in October 2019. Rather than relying on opinion or broad correlations, it used an event-study design — a well-established technique in financial economics that measures how a company’s performance changes around a specific, datable event.
The analysts examined 5,825 newly appointed senior executives — CEOs and CFOs — across corporate America, of whom 578 were women (about 10% of the total, itself a telling indicator of how rare female appointments still were). They then tracked each firm’s financial performance over the 24 months following the appointment, comparing outcomes for firms that appointed women against the broader market.
The results were consistent and substantial. Firms that appointed female CFOs saw:
- 6% greater profitability than the market average over the two-year window;
- 8% larger stock returns;
- and, in aggregate across all such firms, an estimated $1.8 trillion in excess profit.
Firms that appointed female CEOs, meanwhile, saw a 20% increase in stock-price momentum in the 24 months after appointment. The pattern held across both top jobs, but the CFO effect on profitability was the most quantifiable and the source of the headline trillion-dollar figure.
Why it is unlikely to be pure coincidence
The natural first objection is that this could be random noise or reverse causation. S&P Global’s design and supporting findings make that harder to dismiss.
First, the effect was measured across nearly six thousand appointments, not a handful of cherry-picked success stories. Large samples wash out the flukes; a spurious result would not persist so consistently across hundreds of female appointments.
Second, the study uncovered a coherent web of related findings that point to a genuine underlying mechanism rather than a statistical accident. Firms with female CEOs had, on average, roughly double the female board representation of the typical company — about 23% versus the market’s roughly 11% at the time. Greater board gender diversity was itself associated with higher profitability and larger firm size. In other words, female leadership at the top tended to travel with broader diversity throughout the organisation, and that broader diversity correlated with strength. This clustering suggests something structural: companies that promote women tend to be companies with better governance and deeper talent pools.
Third, the direction of the effect is consistent with a large independent literature — the Peterson Institute’s global survey, McKinsey’s diversity research — all of which find gender-diverse leadership associated with equal or better performance. When multiple independent research teams using different data and methods reach compatible conclusions, coincidence becomes a strained explanation.
The interpretations that make sense
If the effect is real, why would a female CFO in particular be associated with stronger profitability? Several complementary explanations are plausible.
One is a selection effect that reflects merit, not bias in the study. Because women face higher hurdles to reach the C-suite — the “glass ceiling” is real and well documented — the women who break through may, on average, be exceptionally capable. When a system filters one group more harshly than another, the members of the filtered group who make it through tend to be unusually strong. A woman who becomes CFO has typically had to outperform to overcome the obstacles men in the same role did not face.
A second explanation concerns decision-making style. Some research associates female executives with more prudent risk management and less overconfident financial behaviour — traits that can protect a firm’s bottom line, particularly a CFO’s core responsibility. This should be stated carefully, as a tendency observed on average rather than a rule about individuals, but it is consistent with the profitability findings.
A third is the organisational-health signal. A company willing to appoint a woman to one of its two most powerful financial roles is signalling, and often possessing, a genuine meritocracy and a modern governance culture. Those underlying qualities — not the appointment alone — may be what drives performance.
The honest caveat
Integrity requires flagging the study’s central limitation, which S&P Global itself acknowledges: this is observational, event-study evidence, not a controlled experiment. It establishes a strong and economically meaningful association between female CFO appointments and superior performance. It cannot definitively prove that the appointment caused the profit. Firms that appoint women may already differ in ways — better governance, more forward-looking cultures, stronger boards — that independently produce both the appointment and the profit. The $1.8 trillion should therefore be understood as the profit generated by a group of firms that chose to promote women, not as a guaranteed return on hiring any particular woman.
That caveat, properly understood, actually strengthens the practical takeaway. Whether female leadership causes the outperformance or merely travels with the qualities that cause it, the message to a board is the same: companies that promote capable women are, on the largest available evidence, systematically among the better performers. There is no serious body of evidence pointing the other way. In a competitive market, ignoring half the talent pool for the top financial job is not neutral — it is a self-imposed handicap.
The behavioural-finance angle, handled with care
The suggestion that female executives bring a distinct decision-making style deserves fuller treatment, because it is easy to slide from a real empirical tendency into a lazy stereotype. What the behavioural-finance literature actually finds is subtle. Some studies associate greater female representation in financial leadership with somewhat more conservative risk-taking, lower likelihood of overleveraging, and fewer value-destroying mega-acquisitions of the kind that overconfident management sometimes pursues. In the specific context of a CFO — whose core job is stewardship of the balance sheet, capital allocation and financial discipline — a tendency toward prudence and away from overconfidence is precisely the trait that protects and grows profitability.
The essential caveat is that these are statistical tendencies observed across large populations, not statements about any individual. Plenty of male CFOs are models of prudence and plenty of female CFOs are bold risk-takers. The point is not that women are innately cautious — a claim the evidence does not support in that essentialist form — but that a leadership team drawing on a wider range of temperaments and perspectives is less likely to march in lockstep off a cliff. Read this way, the behavioural angle is really another version of the diversity argument: heterogeneous teams make better collective decisions than homogeneous ones.
What it means for the appointment pipeline
The S&P Global finding also carries a practical lesson about the supply of female financial leaders. The study noted that only about 10% of the executive appointments it examined went to women — a scarcity that is itself a strategic problem. If firms with female CFOs tend to outperform, then the systematic under-promotion of women into financial leadership represents a competitive handicap that companies impose on themselves. The finance function has its own pipeline, running from analyst through controller and treasurer to CFO, and women thin out at each step much as they do in the general management pipeline. Companies that want to capture whatever advantage the S&P data describe cannot simply wait for female CFO candidates to appear; they have to build the pipeline deliberately, ensuring women get the controller and divisional-finance roles that are the normal proving ground for the top job.
The wider pattern of corroboration
The reason this study should be taken seriously rather than dismissed as a one-off is that it does not stand alone. Its direction is consistent with the Peterson Institute’s finding that women in the C-suite specifically (rather than on boards) drive the profitability association; with McKinsey’s repeated finding that executive-team gender diversity correlates with a higher likelihood of financial outperformance, a correlation that has strengthened across successive editions; and with Credit Suisse and other financial-institution research reaching compatible conclusions. When independent teams, using different datasets, time periods and methods, keep finding the same directional relationship, the probability that all of them are capturing pure noise becomes vanishingly small. The individual studies each have limitations; their convergence is what makes the overall pattern credible.
The scarcity that makes the finding matter
Set the profitability question aside for a moment and the raw representation numbers tell their own story. The CFO role is one of the two most powerful positions in any company, and it remains overwhelmingly male. Across large listed companies globally, women hold only a modest fraction of CFO seats — a share that has risen but remains far below parity — and the CEO role is scarcer still, with women holding well under one in ten of the top jobs at the world’s largest companies. This scarcity is the backdrop against which the S&P Global finding acquires its force. If female financial leaders were plentiful, an outperformance finding would be a curiosity. Because they are rare, the finding describes a systematically underexploited opportunity: a category of leader associated with strong performance whom companies nonetheless promote far less often than the numbers would justify. The persistence of the scarcity, in the face of evidence that these leaders perform well, is itself the clearest sign that something other than merit — bias, narrow networks, a leaky pipeline — is governing who reaches the top of the finance function.
From a single statistic to a strategy
For a company that takes the S&P Global finding seriously, the practical response is not to fixate on the headline number but to treat it as a prompt to examine its own pipeline. Where do women drop out of the finance track — at the move into management, into divisional finance leadership, into the controller and treasurer roles that feed the CFO seat? Are high-potential women being given the profit-and-loss responsibility and the stretch assignments that the top job requires, or are they being steered into support functions that look important but do not lead upward? Is succession planning drawing candidates from the whole pool or defaulting to familiar names? These are answerable questions, and answering them is how an interesting research finding becomes an operational advantage. The trillion-dollar figure is memorable, but its real value is as a door into a harder and more useful conversation about how a specific company builds, or fails to build, the female financial leadership that the evidence rewards.
It is worth situating this finding in the broader arc of how the “business case” for diversity has evolved. A decade ago, advocates leaned heavily on such studies, arguing that companies should promote women because it would boost the bottom line. That framing has since drawn thoughtful criticism: if the case for treating women fairly rests entirely on profit, it becomes conditional — vulnerable to the next study that finds a smaller effect, and implicitly conceding that fairness needs a financial justification at all. The more durable position treats findings like S&P Global’s not as the reason to promote women but as reassurance that doing so carries no performance penalty and very likely a benefit. Equal opportunity is worth pursuing on its own terms; the value of this research is that it removes the last excuse of those who claim fairness must be traded against results. On the evidence, there is no such trade-off to make.
It should also be noted that this is a 2019 study, and it remains the most-cited analysis producing this specific trillion-dollar figure; there is no more recent restatement of the number, so it should always be quoted with its year. But the underlying finding — that firms elevating women to the C-suite tend to win — has been corroborated repeatedly since. Far from a coincidence, it is one of the more robust patterns in the study of corporate performance.
Sources: S&P Global Market Intelligence, When Women Lead, Firms Win (October 2019); S&P Global #ChangePays research series; corroborating evidence from the Peterson Institute (2016) and McKinsey (Diversity Matters Even More, 2023).
