Institutional background
The study is embedded in the German corporate governance context. Germany features a two-tier system of governance. The management board (Vorstand) headed by the CEO (Vorstandsvorsitzender) manages the entire company and determines its policies and strategies. The SB (Aufsichtsrat) monitors and advises the management board, appoints and recalls members of the management board, performs auditing and reporting functions, and convenes the annual shareholder meeting.Footnote 4 In addition, the SB decides the level and structure of the compensation for the management board (AktG. § 111, Bundesministerium der Justiz und für Verbraucherschutz 1965). Therefore, the supervisory board fulfils the obligations of a compensation committee of firms in, e.g., the USA.
The German Corporate Governance Codex does not require firms to establish a CC (Verguetungsausschuss). Yet, given the immensity of duties of the SB, many firms set up such a committee (Bachmann 2020). Members of the CC must be members of the SB so that the former is a sub-committee or working group of the latter. The committee reports to the SB, which eventually decides CEO compensation. Therefore, the SB can be considered the compensation-setting authority.
The strict distinction between management and supervision differs fundamentally from the one-tier system, for example, in the USA or UK, where the board performs both functions. Hence, Germany represents a unique empirical setting to investigate the influence of social relationships and group dynamics on CEO compensation.
Sample
For the present study, German companies listed in the Dax-30, M‑Dax, and S‑Dax were considered. The sample period spans the years 2013 to 2016. We collected the following data for the chairperson of the management board (CEO), the chairperson of the SB, and the members of the SB: year of birth, gender, place of birth, nationality, place of residence, subject area, degree, title, city (of education and work), previous companies, previous positions, voluntary activities, hobbies, and the respective period (of the education, the positions and the stays in cities). Data sources are Munzinger Database, CVs published on the websites of previous and current employers, and the LinkedIn networking platform. CEO compensation and several control variables (number of employees, return on assets) were extracted from corporate reports for the respective years.
We started the data collection with 30 Dax companies, 50 M‑Dax, and 50 S‑Dax companiesFootnote 5. However, as we could not collect biographical data for all CEOs and SB members, the number in our sample amounts to 27. Not taking all companies into account could lead to a selection bias. Therefore, we conducted the Heckman test for panel data models based on Semykina and Wooldridge (2010). However, the test only considers missing data of the dependent variable. Therefore, we set social relationships as the dependent variable and tested whether the structural conditions of the companies in the sample are more likely to lead to social relationships. More precisely, we tested how the model \(\textit{CEO\,SB\,All\,SR}=\textit{Total\,Compensation + No.\,of\,Employees}+\textit{RoA}+\textit{CEO\,Age}+\textit{CEO\,Title}+\textit{CEO\,Change}+\epsilon\) fits the selection model \(\textit{Exists\,in\,Sample}=\textit{Total\,Compensation}+\textit{RoA}+\textit{Balance\,sheet\,total}+\epsilon\). For this test, we were not able to collect CEO compensation for all 130 companies. Therefore, we could not consider 13 companies from the M‑Dax and 21 companies from the S‑Dax. In addition, Deutsche Bank (Dax-30) could not be considered because the change from a double to a single CEO distorted the amount of compensation. Furthermore, the companies SAP and freenet show outliers regarding the total compensation of the CEO and are, therefore, not considered either.Footnote 6 As a result, the Heckman test for panel data models shows that the interaction of the inverse Mills ratios with the time variable is not significantly different from zero (\(p> 0.999\) for each year). Thus, we assume that there is no selection bias. Moreover, we can add another argument to corroborate our assertion. In our sample, the majority of individuals do not have social relationships with other individuals.Footnote 7 This means that not only individuals who have more social relationships (i.e., similarities concerning recreational interests, education, etc.) with others are willing to provide information about these relationships, but individuals with few or even without such relationships make their recreational interests and educational background public. Eventually, our sample consists of 560 persons from 25 companies. Table 1 presents an overview of companies in the sample.
Table 1 Companies in the sample Table 4 in Sect. 3.3 provides an overview of the data set’s characteristics.
Variable operationalization
CEO compensation
Likewise Westphal and Zajac (1995), Hwang and Kim (2009), Fracassi and Tate (2012), we use Total Compensation to measure the compensation of the CEO, which is our dependent variable. In particular, total compensation according to the German Corporate Governance Code is used. It includes all monetary compensation components, options and other share-based componentsFootnote 8, pension benefits, other commitments (in particular in the event of termination of employment), fringe benefits of any kind, and benefits from third parties promised or granted in the financial year with regard to the activities of the Management Board (Regierungskommission Deutscher Corporate Governance Kodex 2017, p. 7).
Types of social relationships
Social relationships are quantified in terms of the characteristics that CEO and members of the SB possess. The characteristics are assigned to different types of social relationships. The types of social relationships most frequently used in the literature are Education, Past or Present Employment, and Other Activities (or Non-Professional Activities), as, for example, in Fracassi and Tate (2012) or Bruynseels and Cardinaels (2014). Following prior research of Hwang and Kim (2009), Fracassi and Tate (2012), and Bruynseels and Cardinaels (2014)), we standardize measurements of social relationships between 0 and 1, where higher numbers indicate stronger ties.
In the literature, there exist different ways to measure the type Education. While some authors focus on the same educational background, in which social relationships arise from the same degree, title, and/or subject area (Westphal and Zajac 1995; Fiss 2006)), others emphasize the same experiences arising from the same school and, at best, from the same school at the same time (Cohen et al. 2008; Fracassi and Tate 2012; Nguyen 2012; Bruynseels and Cardinaels 2014). In our view, each approach highlights a relevant aspect. Therefore, we split the type Education into type Educational Background and type Educational Experience.
Our measurement of type Educational Experience is based on Cohen et al. (2008), who distinguish four possible characteristics that give rise to a social relationship of that type. They differ with respect to the strength of the effect on the social relationship: (i) the same schoolFootnote 9 (weakest lasting effect), (ii) the same school and the same degree, (iii) the same school at the same time, and (iv) the same school at the same time and with the same degree (strongest lasting effect). We assign increasing weights to these characteristics, given that the effect associated with them is becoming more robust from subtype (i) to (iv). Therefore, social relationships corresponding to subtypes (i), (ii), (iii), and (iv) were multiplied by 1, 3, 6, and 10, respectively. The weights reflect an increasing marginal effect of the similarities on building a social relationship. This approach is in line with Fracassi and Tate (2012), who restrict education connections to subtypes (iii) and (iv). Finally, the total score of social relationships obtained as the normalized sum of these weighted relationships divided by the number of individuals. Consider a group of six individuals in which five show education connections; then we determine for each individual the connection of the highest type to another individual. Assume two of them are connected via type (iv), two others have a type (ii) connection, and one individual shows a connection of type (i) to another individual (that has yet another connection of a higher type to another individual). The total score amounts to \((1\cdot 1+2\cdot 3+0\cdot 6+2\cdot 10)/(10\cdot 6)=9/20\).Footnote 10 Since we could not identify the school in each case, we use the city in which the individuals graduated as a proxy instead. Table 2 presents a summary of the types we deploy.
The measurement of type Educational Background takes the degree, title, and specialization (subject) into account. Table 10 in Appendix 2 provides an overview of subjects. The calculation of the score for this type follows the same procedure as for type Employment and Other Activities.
We measured the types of social relationships Past or Present Employment and Other Activities (or Non-Professional Activities) similar to Fracassi and Tate (2012) and Bruynseels and Cardinaels (2014). Social relationships based on present employment arise if two persons in a company (e.g., CEO and chairperson of SB of company A) hold the same position in other companies. For example, if the CEO serves as an external director in company B and the chairperson does so in company C. Such social relationships also arise if they have different positions within the same company D. For Past Employment, companies worked for and positions held before joining the sample firm are relevant. Analogous to Bruynseels and Cardinaels (2014), in this study, the social relationships based on past or present employment collectively define the type Employment.
Social relationships based on other activities are, for example, shared memberships in clubs or charities (Fracassi and Tate 2012). For a detailed list of characteristics of type Other Activities cf. Table 9 in Appendix 1. Likewise Fracassi and Tate (2012) and Bruynseels and Cardinaels (2014), we did not set time restrictions for other activities. Most people very likely perform these activities on a long-lasting basis; thus, we assumed they performed them in the period under consideration.
Table 2 Types and characteristics In the following, we illustrate the measurement of social relationships (SR) using type Other Activities. First, we do so for social relationships between the CEO and the SB, the CEO and the SB chairperson (SBC), as well as between the CEO and the SB members (SBM i–vi). Social relationships between CEO and all SB members (including the chairperson) are measured as follows: If at least one activity of the CEO is identical to an activity of a member, it is coded with 1. When all activities of the CEO are compared with all members’ activities, the sum of the identical activities is then divided by the number of members of the SB (including chairperson). The social relationships between the CEO and the SBC, CEO and SBM (i–vi), and between SBC and SBM are determined analogously (see Table 3).
Table 3 Measurement of social relationships (SR): Type Other Activities of a sample company Second, we explain the measurement of social relationships within the SB (SBM i–vi). Fig. 1 illustrates the measurement. First, a member is selected for whom an activity is given (here member 1). This activity is compared with the other members step by step. If there is a first match with a member for this activity, the connection is set to 2 because two members perform the same activity. If another match between the member and another member exists, the connection is set to 3. This process continues until all members have been checked. Next, a member is selected with whom a connection already exists (here member 3). This member’s activities will be compared again with all members (except member 1). If there is a match, the number of connections is increased by 1 again. Once all members who have a connection with member 1 have been checked, those who have a connection to member 3 are checked. This process continues until all members have been checked for matches. If there are members left who have activities listed, we compare them with the remaining members who have not yet been compared. Finally, the highest number of connections is chosen and divided by the number of members. In the example in Fig. 1, the strength of the social relationship type Other Activities between member one and the other board members is \(3/6\).
Hwang and Kim (2009), Fracassi and Tate (2012), and Bruynseels and Cardinaels (2014) aggregate the connections based on the different types of relationships to a single variable. This aggregation increases the statistical power of the variable, but it gives equal weight to the impact of the different types (Fracassi and Tate 2012). Therefore, Bruynseels and Cardinaels (2014) test the aggregate impact and the impact of the individual types. They find that the different kinds of relationships do not have the same effect on the power of the CEO (Bruynseels and Cardinaels 2014). For this reason, we consider both the effect of individual types of social relationships and the aggregate measure of types in the analysis. The variable All SR describes the aggregate measure of types of social relationships. This variable is different from zero for every CEO in the sample.
Control variables
Following Belliveau et al. (1996), Fiss (2006), Hwang and Kim (2009), and Fracassi and Tate (2012), we use the following control variables: CEO Age, CEO Title, CEO Change, Board Change, Board Size, No. of Employees and return on assets (RoA). CEO Title refers to the education level of the CEO and is intended to control for a higher salary based on a title (Fiss 2006). The variable CEO Change controls for a higher salary due to a change of CEO. This variable is a binary variable and is one if there was a change of CEO in the year under consideration. The variable Board Change controls for changes in the compensation of the CEO due to a change in the members of the SB. This variable is measured analogously to the variable CEO Change. No. of Employees controls for company size and RoA for company performance.
Table 4 Characteristics of the data set Regression model
The collected data has a panel structure consisting of observations from several companies at several consecutive points in time. It should be noted that for regression analysis, our dependent variable Total Compensation could be influenced by its time-lagged values, i.e., by compensation in previous periods. The use of the Arellano–Bond estimator in dynamic panel models would take this effect into account (Bond 2002; Arellano and Bond 1991). However, upon using this method, our sample size reduces because we loose observations of two years.Footnote 11 Since only the observations of two years would remain to estimate the influences of social relationships, we decided against the Arellano–Bond estimator. Instead, we deploy the fixed-effects model to estimate the regressions. This model takes into account all four years of our sample. (The random-effects model is inappropriate due to a necessary requirement not being met. For details, see the next two paragraphs.) The estimator may nevertheless be biased due to the issue described.Footnote 12
We estimate different regression models using the aggregate measure of social relationships or the individual types of social relationships. We also estimate moderation effects in the latter models.
We tested the regressions for (i) endogeneity with the Hausman test, (ii) homoscedasticity with the Goldfeld-Quandt test, (iii) serial correlation with the Breusch-Godfrey/Wooldridge test, and (iv) normal distribution with the Shapiro-Wilk normality test. Table 11 in Appendix 3.1 summarizes results and measures taken to circumvent any problems with regression requirements.
Owing to the heteroscedasticity in all models, we used the fixed-effects model for each regression. The inconsistent covariance estimates were recovered by the heteroscedasticity-consistent covariance matrix estimation using the method of White (White, 1980; Millo, 2017; Zeileis, 2004). The results of the regressions of Sect. 3.5 contain consistent covariance estimates. The Shapiro-Wilk normality test indicates that the residuals of some of the regressions are not normally distributed. Consequently, the normal distribution of residuals of all models is additionally verified graphically as well (cf. Fig. 7 in Appendix 3.2). These graphs show that the residuals behave similar to a sample from a normal distribution. Thus, a normal distribution of all models can be assumed (Wilk and Gnanadesikan, 1968; Thode, 2002).
The models were also tested for multicollinearity (cf. Fig. 2). Some type-based social relationships between the CEO and SB members are significantly positively correlated with each other. In addition, social relationships within the SB often correlate significantly positively with social relationships between the CEO and the SB members. The strength of the correlation in both cases can be classified as moderate.Footnote 13 Additionally, we computed the variance inflation factors (VIF values; cf. Tables 12, 13 and 14 in Appendix 3.3). Values greater than 5 for the interaction term and the related variables are normal, expected, and inevitable. The models do not indicate multicollinearity between the independent variables.
Results
Table 5 shows the regression related to Hypothesis 1. Social relationships (SR) between the CEO and the entire SB (chairperson and members) were analyzed, disregarding the SR within the SB and between the CEO and the chairperson of the SB. We later accounted for these SR in a separate model.
Table 5 Regression results (fixed-effects): Model (1) & (2) Model (1) shows a significant negative influence of SR (CEO SB All SR) on Total Compensation. Therefore, the results do not support Hypothesis 1. Similarly, we obtain ambiguous results in Model (2), where we regress on the different types of SR. There is a significant positive effect of type Employment but a significant negative effect of type Educational Experience and type Other Activities on Total Compensation. Type Educational Background is not statistically significant. It appears that the different types of SR affect CEO compensation differently. As the effects and direction of the effects of different types show either positive or negative signs, Hypothesis 1 also cannot be confirmed in Model (2).
Table 6 presents the results concerning Hypotheses 2a and 2b. For these hypotheses, we analyze the SR between the CEO and the SB members without the chairperson of the SB. The chairperson of the SB is excluded to avoid a possible bias due to her/his dominant position. Notwithstanding, the results of Models (3) and (4) are comparable with Models (1) and (2). We find that a significant negative effect of SR (CEO SBM All SR) in Models (1) and (3) no longer exists when the relationships within the SB are considered. The same applies to the significant influences of types Employment, Educational Experience and Other Activities in Models (2) and (4). Therefore, Hypothesis 2a cannot be confirmed.
In Models (5) and (6), the moderation effect of SR within the SBM was tested. The results of Model (6) show a significant positive influence of the moderator variable CEO SBM Educational Background\(\times\)SBM Educational Background on Total Compensation. However, one cannot interpret this influence without accounting for the level of the respective SR. Because of the standardization of variables, the level of SR among the SBM or between CEO and SB is low (high) when its value is close to 0% (100%).Footnote 14
Table 6 Regression results (fixed-effects): Model (3), (4), (5), & (6) Fig. 3 visualizes the moderation effect. A high level of SR based on Educational Background between the CEO and the SB members leads to an increasing compensation if SR among the SB members increase. There exists a threshold of 0.88 for the strength of SR between SB members such that CEO compensation is higher if the CEO has SR with SB members compared to a situation without SR. Additionally, if SB members have only very few SR with each other, CEO compensation is higher, the lower the level of SR between CEO and SB members.
Hypothesis 2b does not find support in the results, possibly because SR based on Educational Background only increase the CEO compensation if almost all members of the SB have SR with each other and the other types of SR show no significant effect.
Table 7 Regression results (fixed effects): Model (7), (8), (9), & (10) Table 7 shows the results concerning Hypotheses 3a and 3b. The SR between the CEO and the SBC and between the SBC and the SBM were analyzed. Model (7) and (8) in Table 7 consider only the social relationships between the CEO and the SBC. The result of Model (7) shows that SR (CEO SBC All SR) between the CEO and the chairperson have no significant influence on Total Compensation of the CEO. When differentiating types of social relationships (Model (8)), Educational Background (CEO SBC Educational Background) shows a significant negative impact on compensation. Hypothesis 3a cannot be confirmed. However, in line with the results for Hypotheses 1 (cf. Table 5) and 2a (cf. Table 6), the results for Hypothesis 3a suggest that the different types of social relationships can have an influence on CEO compensation. In Model (9), the moderation effect of SR between the SBC and the SBM is considered (CEO SBC All SR\(\times\)SBC SBM All SR). Here, the results are the same as in Model (7). Model (10) indicates that SR based on type Employment between the CEO and the SBC significantly increase the compensation of the CEO if SR between the SBC and the SBM are considered (CEO SBC Employment\(\times\)SBC SBM Employment). We find a similar moderation effect for SR based on type Same Educational Experience (CEO SBC Same Educational Experience\(\times\)SBC SBM Educational Experience). In addition, the results of Model (10) document a statistically significant, negative influence of the moderating variable CEO SBC Other Activities\(\times\)SBC SBM Other Activities on total compensation. Again, the interpretation of the different effects of these moderating variables must take the level of the respective SR into account. We use the same approach as for the results of Model (6).
Fig. 4 visualizes the moderation effect of SR based on type Employment between the CEO and the SBC; Fig. 5 does so for type Educational Experience. Surprisingly, the effect of closer ties between CEO and CSB is not as straightforward as expected. It takes a certain level or strength of social relationships between SBC and SB members such that closer social ties between CEO and SBC pay off for the CEO. Consequently, Hypothesis 3b finds support for SR based on type Employment and type Educational Experience. However, if there are no SR between CEO and SBC of type Employment, a more socially connected SB is associated with lower CEO compensation. The picture becomes even more dismal from the CEO’s perspective for SR of type Other Activities. Given a modest level of SR between SBC and SB members, CEO compensation decreases if the level of SR between CEO and SBC increases (Fig. 6). Hypothesis 3b cannot be confirmed for SR based on type Other Activities.
The significant moderation effects highlight the importance of group dynamic processes in the CEO compensation-setting process. Furthermore, the type of SR has a role to play in this process. When considering an aggregate measure of SR, we see a negative impact of SR on CEO compensation – in contrast with our hypotheses. If this effect is statistically significant, it can be attributed to SR of type Educational Experience and Other Activities. It reiterates the fact that the type of SR matters for the level of CEO compensation. Table 8 summarizes the statistically significant findings of our study.
Table 8 Summary of statistically significant results