3.1. Analysis Framework
There might be several reasons for CEO turnover. Some CEO departures occur because of managerial behaviors that arise from managerial power, tournament perspectives, or the insider trading of executives, as analyzed in the previous section. Other CEOs are dismissed for reasons such as a CEO’s low ability, personal scandals or violations of laws. Many CEOs depart voluntarily, e.g., accepting a better offer elsewhere or retiring. In reality, firms are not required to disclose the true reason for a CEO dismissal and are less likely to do so when firing a CEO. To distinguish between CEO departures induced by managerial pay disparity and other reasons, we introduce a concept of pay-gap-induced turnover, which refers to the replacement of top management motivated by either the level of the CEO’s power or the scale of the tournament prize.
Conceptually, the probability of CEO turnover is modelled as the sum of two independent turnover probabilities, one of which is connected to the CEO pay slice and the other one is related to other determinants. Here, the CEO pay slice is calculated as the difference between the total pay of the CEO and the average pay of the other four senior executives, divided by the total pay of the top five executives. We denote this measure of CEO pay disparity as
xt (
xt ≥ 0). The probability of CEO turnover is modelled as follows:
where
is defined as the total probability of CEO turnover;
is the CEO
pay-gap-induced turnover; and
F(xt) is the probability of CEO turnover caused by other reasons.
The assumption, under the managerial power theorization, is that xt reflects a CEO’s ability to capture managerial power. Higher ability earns larger managerial power and, therefore, increases succession risk. We assume that when xt is at or above a specific level of executive pay disparity, say , the CEO is more likely to entrench himself by obstructing the career development of other executives and not being willing to groom high-quality CEO, potential successors. We let κ = xt − denote the incentive level at which any value of κ ≥ 0 is considered an incentive for the CEO to dominate other executives, behave opportunistically and entrench their CEO position. At a large enough level of CEO pay slice, such as the 80th percentile of the pay slice distribution, all turnovers observed at and above the large level are assumed to be unrelated to the managerial power of the CEO. Any higher turnover probability observed at the level below large is assumed to be caused by the lower level of managerial power of the CEO and, hence, their relative disposability. Therefore, the incentive level at large is defined as κlarge = xt − large
We derive the empirical implications that arise in this framework from combining pay-gap-induced turnover with other sources of turnover.
The likelihood that CEO turnover is decreasing in the CEO incentive levels is given by the following constraint:
The probability of
pay-gap-induced turnover is zero at or above the large CEO pay slice
large is given by the following constraint:
The managerial power theory perspective predicts that for any level of CEO pay slice
xt, the returns to insider purchases are a credible signal of future CEO turnover. They are negatively associated with the probability of CEO departures; therefore, the likelihood of CEO turnover is decreasing in the returns to insider share purchases
rpurchases.
The results derived in implication 1 (i) and (ii) follow immediately from the managerial power theory. Statement (i) establishes a negative relationship between the CEO pay slice and turnover. This is a standard prediction of the relationship between managerial power and CEO entrenchment. The result would hold true under the managerial power theory perspective when a higher pay disparity reflects the stronger power of the CEO (
Bebchuk et al. 2011;
Chen et al. 2013), thereby increasing CEO succession risk (
Chen et al. 2013). The prediction carries over to our setup because the CEO is less likely to leave when the CEO pay slice remains high. Statement (ii) characterizes the abnormal returns to insiders’ purchases as signals of CEO entrenchment. The prediction suggests that the CEO is less likely to depart after reaping high returns on their own purchases of their employer’s stock.
In contrast to the managerial power theory perspective, xt represents the tournament prize, which motivates other executives to work hard and compete for the CEO position. We denote κ′ = xt − ′ as an incentive prize. At any value of κ′ ≥ 0, the other executives have an incentive to win the contest for promotion to higher levels. All the CEO exits observed below the level of ′ are assumed to be unrelated to executive pay disparity. Any other turnover of our CEOs, observed at or above ′, is assumed to be caused by the attempts of other executives to compete to attain the tournament prize. Hence, the following empirical implication simplifies the theoretical predictions for the tournament theory perspective.
The probability of CEO turnover is increasing in the managerial incentive prize. So
The probability of
pay-gap-induced turnover is assumed to be zero at the level below the tournament prize
′
prize, which is considered a starting point of the prize to induce other executives to enter the contest.
κ′
prize is defined as the level of incentive prize equal to
xt −
′
prize.
The likelihood of CEO turnover is increasing in the returns of insider sales
rsales.
The first two statements in Empirical Implication 2 follow immediately from the tournament theory perspective. Statement (i) establishes a positive association between CEO turnover and the tournament prize measured by CEO pay disparity. Specifically, the model predicts that firms with a larger pay disparity tend to motivate other executives to compete for higher positions, thereby increasing the likelihood of CEO turnover. Statement (ii) predicts that at, or above, some high pay disparity level, contestants can attempt to pursue the CEO position by all means, even engaging in political sabotage to smear the CEO’s reputation. Statement (iii) characterizes the abnormal returns of insiders’ sales as the signals of forthcoming CEO dismissals. This prediction suggests that a CEO is more likely to be dismissed after large insider sales returns.
In order to investigate the impact of managerial pay disparity and insider trading on CEO turnover in a panel data environment, the likelihood of CEO turnover can be expressed by a modification of the standard probit model, which is stated below.
where the dependent variable is 1 if the CEO turnover occurs in year
t and 0 otherwise.
is the standard normal cumulative distribution function,
i denotes each firm, and
t represents the calendar year. The independent variable
is average insider abnormal returns of firm
i in year
t − 1, pay with respect to the total pay of the top five executives.
denotes a vector of control variables. The definitions and measurements of the various variables are introduced in the next section.
3.2. Sample Selection
We gather information on insider transactions, managerial pay disparity, and CEO demographics (e.g., ages, tenures, CEO duality) from the Bloomberg database (
Bloomberg L.P. 2020). Data pertaining to the firms’ specifics, such as firm size and stock price, are collected from Refinitiv DataStream (
Refinitive DataStream 2020). CEO turnovers are manually collected from firms’ annual reports.
Our sample represents the largest companies listed on major indices from eight countries: FTSE 100 (UK), DJIA (US), TSX 60 (Canada), ASX 50 (Australia), DAX (Germany), CAC 40 (France), AEX (Netherlands), and BEL 20 (Belgium). The sample period is between 2008 and 2019, which coincides with the most severe global financial crisis, 2008–2010, since the Great Depression. This crisis had a profound impact on the global economy, including on executive compensation and CEO turnover rates. Moreover, this period witnessed an increasing awareness and activism around social justice issues, specifically the diversity and equity inclusion agenda. Particularly, income inequality and calls for social justice may have contributed to a heightened focus on the CEO pay gap. Furthermore, significant shifts in business models towards digitalization, and globalization occurred during this time, leading to increased competition that may have impacted CEO turnover rates.
Our final sample size is determined by specific criteria. Firstly, we require compensation data for the top five executives to be available. In cases where information on compensation is missing for any executive in a particular year, the data for that year will be excluded. Secondly, if firms are listed on multiple markets, we only retain the data from their primary listing market and remove the data from alternative markets. Finally, firms that were listed, or delisted from the indices after the study period commenced are also excluded. Through this screening process, our final sample comprises 2655 firm-year observations, derived from 23,310 insider transactions within 295 firms over an eleven-year period from 2008 to 2019. This dataset is further divided into 7377 insider purchases and 15,933 insider sales sub-samples.
3.3. Models and Measurements of Variables
We employ a probit model to examine the relationship between CEO turnover and several key independent variables. The dependent variable in our model is a binary variable that takes a value of 1 if the CEO left the firm in a fiscal year and 0 otherwise. Our key independent variables are the CEO pay slice, defined as the managerial pay disparity of the top five executives in the management team, and insider returns of the non-CEO executive in the top management team. In addition, we include three commonly used CEO characteristics that are known to influence CEO turnover: CEO age, tenure and CEO/Chair position duality. We also incorporate various firm fundamental variables as control variables, including firm size, accruals, free cash flow per-share, and the Tobin Q ratio. In order to calculate the average insider returns of non-CEO executives, we conduct an initial test using an event-day-study methodology. This allows us to analyse the stock price movements surrounding insider transactions and to evaluate the behaviour of insiders based on insider returns.
To measure insider abnormal returns, we use the market model (as described in (
Brown and Warner 1985;
MacKinlay 1997) and many subsequent studies) as it is widely accepted in the research literature. We estimate insider returns over five different event horizons: 60-day, 90-day, 120-day, 150-day and 180-day periods between day
t + 1 and
t + 180. The insider return of each transaction is defined as the abnormal return (
RETit) for sample firm
i on the day
t, which is measured as follows:
where
Rit is the actual returns of firm
i on day
t.
MRt is the market return on day
t.
θ is a binary variable for the direction of trade, which takes the value of +1 if the trade is a “Buy” and −1 if it is a “Sell”. The insider abnormal returns for sales are multiplied by −1 due to the fact that insiders make abnormal profits when share prices fall after insider sales. The average insider returns (
ARETit) is calculated as the weighted average of total returns,
RETit, insiders made in a given year.
where ARET60, ARET90, ARET120, ARET150 and ARET180 denote average insider abnormal returns for a horizon of 60, 90,120, 150 and 180 days, respectively.
We measure executive pay disparity as total CEO compensation divided by the total compensation of the top five executives. We focus on cash compensation for several reasons. First, cash compensation is used in previous studies (
Eriksson 1999;
Bognanno 2001;
Shen et al. 2010). Second, it is easy to calculate. Third, cash compensation is robust to future movements in the share price and earnings that will influence stock options and long-term incentive plan payouts, which could induce a correlated error in the pay slice metric, inducing an unwanted endogeneity in reported tests.
We control for CEO characteristics using three wide measures—CEO age, tenure and duality.
Coates and Kraakman (
2010) and
Jarva et al. (
2019) document that CEO age is more important in explaining CEO turnover than measures of firm performance. These studies suggest that the probability of a CEO leaving office is positively associated with the CEO’s age.
Jarva et al. (
2019) also find evidence of a negative association between CEO age and enforced CEO turnover and a positive association between the age of a CEO and voluntary turnover. Regarding CEO tenure,
Coates and Kraakman (
2010) and
Jenter and Kanaan (
2015) argue that long-tenure CEOs should have proven their ability in both good and bad times; thus, tenure should be negatively related to the probability of CEO turnover. Finally, we include a dummy variable of duality indicating whether the CEO is also the board Chair. It takes a value of 1 when the CEO holds the board chair position and 0 otherwise.
Zajac and Westphal (
1996) and subsequent literature find that CEOs who hold the chair position concurrently tend to have more subsequent appointments to boards due to their greater control over management. Consistent with prior literature, we expect the CEO who holds the chair position to display a higher level of entrenchment.
Following extensive empirical literature on corporate finance, we use a number of control variables that have been documented to influence CEO turnover, including accounting accruals, operating cash flow per share, Tobin’s Q ratio, tenure and firm size (
Anderson et al. 2018;
Jenter and Kanaan 2015;
Jenter and Lewellen 2014; among others).
Earnings management, proxied by accruals, represents the earnings portion that the managers can discretionally exercise under an auditor’s supervision. Earnings management suggests that CEOs take action by increasing accounting earnings, thereby entrenching their position. If CEOs are dismissed for poor firm performance and have discretion over the performance measures used by the board in termination decisions, then the CEOs who face a high probability of being dismissed will have incentives to adjust accounting accruals in their favor. As such, an increase in accounting accruals is evidence of the amount of managerial discretion of the CEO.
To control for firm performance, we include the operating cash flow per-share, denoted as OCFPS. We include Tobin’s Q ratio to capture the firm’s growth prospects. CEO tenure is included in our model to reflect the impact of firm performance on CEO turnover. Finally, we measure firm size using the natural logarithm of market capitalization. We expect that the CEO of a larger firm has a lower probability of entrenchment due to a higher level of supervision through a larger board.
We employ the probit model to assess the impact of the CEO pay disparity and insider trading returns of non-CEO executives on the probability of a CEO’s exit from the firm. CEO turnover is identified when the CEO of a firm is different from the CEO in the preceding year. To avoid the incidental parameters problem, which arises in the context of nonlinear panel models, we do not include fixed effects in the probit models (
Minton 2012;
Jenter and Lewellen 2014). It is noteworthy that
Chung et al. (
2024) report that the CEO pay slice and firm performance may have a U-shaped relationship. Our main regression model can be expressed as follows:
where
is the standard normal cumulative distribution function,
i indicates a particular firm and
t denotes the financial year. The dependent variable of the model is CEO turnover, which takes a value of 1 if the CEO left the firm in a fiscal year and 0 otherwise. The independent variables are defined as follows:
is the average abnormal returns of non-CEO executives of firm
i at year
t − 1,
is defined as a CEO pay slice of firm
i at year
t − 1 and
is the interaction of the first two independent variables.
is the natural logarithm of CEO age,
is the natural logarithm of CEO tenure, measured as the number of years that the CEO has held the CEO position,
is CEO duality that takes a value of 1 if the CEO also serves as board Chair at the same time and 0 otherwise. The variables
,
and
are defined as accounting accruals, operating cash flow per share and firm size of firm
i at year
t − 1, respectively.
is measured by Tobin’s Q ratio of firm
i at year
t. The variable definitions are summarized in
Table 1 below.