1. Introduction
Agency conflicts occur in corporate governance when the interests of agents (such as administrators or managers) are not aligned with the interests of principals (usually the shareholders or owners) [
1]. As companies develop and grow, the separation between ownership and control occurs almost naturally, which can compromise the company’s performance. While more concentrated structures may alleviate this problem, they can also overshadow the interests of minority shareholders; there exists a trade-off [
2]. As concentration increases, this conflict tends to diminish; however, a new conflict arises, that of personal appropriation by controlling shareholders at the expense of company performance, which affects minority shareholders.
These relationships gained prominence starting in 1976 with the first studies [
1] on the influence of ownership structure on company performance. Since then, studies have been replicated in different locations and contexts [
3,
4,
5]. The importance of ownership structure was consolidated in these studies; however, the analyses were conducted globally [
6,
7], across the entire economy, without specific sectoral analyses. This research analyzed the ownership structure specific to the Brazilian electricity sector, filling a gap in the literature. Understanding how it influences the Brazilian electricity sector can contribute to improving the performance and efficiency of electricity companies, making them more competitive and sustainable. This can indirectly contribute to improving the efficiency of electricity companies and help reduce dependence on fossil fuels. Another contribution of this research is to provide information for the development of public policies by sector regulatory bodies. Understanding how the ownership structure interacts within the sector can inform managers’ decision-making. Everyone—government, managers, users, and society as a whole—can benefit from the results of this research; an efficient electricity sector is beneficial to all stakeholders; everyone consumes electricity, and improving efficiency can help reduce pollution and contribute to reducing pollutant emissions.
The Brazilian electricity sector encompasses the generation, transmission, distribution, and commercialization of electric power. This energy chain is fundamental for sustaining the country’s infrastructure and economic development. According to the 2022 National Energy Balance (BEN), the Brazilian energy matrix is predominantly composed of renewable sources, reaching 78%. The global average, according to data from the International Energy Agency (IEA), is around 29% [
8].
The electricity sector is crucial for the economy, as it enables the production and consumption of energy by businesses and individuals. Given its significance, in 1998, B3 launched the Electric Energy Index (IEE B3), aiming to serve as an indicator of the average performance of the more negotiable and representative assets in the electricity sector. As of April 2024, the companies included in the index represented a market value of
$75 billion [
9].
Studies have demonstrated the relationship between ownership structure and efficiency [
10], although without sectoral analysis, which is the distinctive feature and objective of this study. This research innovates and differentiates itself by examining the relationship between ownership structure and other company indicators through a sectoral analysis of the electricity sector using econometric techniques.
The research problem is presented in the form of a question: Does ownership structure influence the indebtedness and efficiency of companies in the electricity sector? In this context, the objective of this research is to investigate whether ownership structure affects the efficiency and indebtedness of electric sector companies in Brazil. The originality of the research lies in contributing to the literature with empirical results on the effects of ownership structure on the electricity sector. Stakeholders and regulators can benefit from the information generated in policymaking and decision-making for the sector; society as a whole can benefit from this information, considering that an efficient electricity sector would help reduce emissions and pollution.
Studies have associated governance/sustainability with ownership concentration [
11], while others have analyzed the link between oligopolies and ownership structure [
12]. Research examining the perceptions of economic actors is found relatively frequently [
13]. In contrast, this study breaks new ground, filling this gap in the literature by analyzing the impact on key sectors of the economy, specifically the electricity sector, considering that the efficiency of this sector can contribute to sustainability, providing information to regulators and stakeholders in decision-making.
The results confirmed the influence of ownership structure on companies in the electricity sector. Regarding efficiency, the relationship was negative; however, as company capital becomes more dispersed, it ceases to influence company efficiency. In terms of debt levels, the relationship was positive and, despite the dispersion of capital, continues to exert influence. These data provide insights to managers of these companies and policymakers for the sector, especially in concentrated companies, where this structure negatively affects company efficiency.
The article was structured into the following sections: Introduction, where the research was presented; followed by the Literature Review, in which the bibliographical references that guided the research were discussed; Methodology, where the techniques used were addressed; Results and Discussion, in which the research findings were presented and discussed; Conclusions, in which the implications and suggestions for future research are commented; and finally, the Appendices and References.
3. Methodology
To achieve the objectives, annual data from Brazilian companies listed on B3 (the Brazilian stock exchange) were collected and analyzed for the period from 1996 to 2023. The collected data encompass all companies listed on B3 in the electric power sector (7777 observations from 38 companies; see
Table A1 in
Appendix A). Data collection was entirely conducted through the Economática
® database (
https://economatica.com/, accessed on 30 August 2025), and the analysis was performed using Stata
® software version 11.
The regression model was based on unbalanced panel data since there are no observations for all variables across all periods, and the data combine cross-sectional and time-series elements. There was a variation in the number of companies active on B3 during the analysis period, with some entering the stock market recently, others privatizing, and some ceasing to exist, alongside mergers and acquisitions contributing to the unbalanced panel. Balanced panels have the same unit over time, while in unbalanced panels, a unit may enter the database and exit before completing the observation period [
27].
Two regression models were generated for the following dependent variables: Return on Equity (ROE) used as a proxy for company performance and Total Debt (ET) measured by the ratio of net income to equity. The independent/explanatory variables will be the percentage of ownership concentration (ownership structure of the primary ordinary shareholder and ownership structure of the five ordinary shareholders). To analyze the separate influences, as the controlling capital becomes dispersed, and considering the correlation between these two variables, they were examined in separate regressions, resulting in two regressions for each dependent variable (ET and ROE). The additional explanatory variables are detailed in the following models. Departing from the model developed by [
28] and adapted for this work, the following econometric models were arrived at:
where
is Total debt;
is Model intercept;
is Natural logarithm of gross revenue;
is Percentage of ownership concentration of the five largest ordinary shareholders;
is Percentage of ownership concentration of the largest ordinary shareholder;
is Tangibility of assets;
is Natural logarithm of gross debt;
is Participation of third-party capital;
is Natural logarithm of net income;
is Natural logarithm of ROA;
is Return on equity; and
is residual vector.
The subscripts
i and
t represent company
i at time
t. Equations (1) and (2) represent the model for debt in relation to C1 and C5. Equations (3) and (4) represent the model measuring the influence of C1 and C5 on ROE, respectively.
Table 1 summarizes the variables used and their main information. The source for all variables was the Economática
® database (
https://economatica.com/, accessed on 30 August 2025).
The values for gross revenue, gross debt, and net income were all collected in U.S. dollars (USD) to avoid inflation effects considering the long analysis period. These same variables (gross revenue, gross debt, and net income) were also winsorized at 5%. Winsorization preserves the influence in the data without compromising the analysis; it allows for the smoothing of potential outliers by replacing them with upper or lower limits [
29]. This avoids the definitive loss of extreme points while adjusting them to values within acceptable limits [
30].
To choose the appropriate panel data model, Lagrange Multiplier/LM test (Breusch and Pagan) were conducted for random effects versus simple regression. F-statistics (Chow test) compared fixed effects versus simple regression. The Hausman test was used for fixed versus random effects [
31].
The next step was to identify high correlation values through the correlation matrix, where values equal to or above 0.8 are considered high, and through the Variance Inflation Factor (VIF) test, where values above 5 indicate the presence of multicollinearity [
32].
The presence of heteroscedasticity was checked using White’s [
33] statistical test modified for panel data [
34]. For autocorrelation of the residuals, the test developed by [
35], based on the work of [
36], was used. In the presence of heteroscedasticity and autocorrelation, it can be corrected using the Feasible Generalized Least Squares/FGLS procedure [
37]. Stationarity was identified through ADF tests adapted for panel data [
38,
39].
4. Results and Discussion
The descriptive statistics are presented in
Table 2. As can be observed, after applying the natural logarithm and winsorizing at 5%, the variables Gross Revenue (RB), Gross Debt (DB), and Net Income (LL) showed means and medians that are very close, indicating consistency in the data.
On average, 29% of the companies’ assets would be committed to covering the total of their debts. The return on assets averages only 7%, corresponding to the electric power sector, which requires significant capital investments. The efficiency of management, measured by return on equity, which assesses a company’s ability to generate value for the business and investors based on the resources the company possesses, was 36%, corroborating the significant return that the sector provides to shareholders. The ownership concentration, represented by the control of the largest and five largest ordinary shareholders, averaged 68% and 89%, indicating a high concentration in the sector and a low free float (the percentage of a company’s shares available for trading on the stock market) despite C1 showing a standard deviation of 23%, indicating significant variability in control exercised by the largest shareholder. The average tangibility of 30% indicates that a large portion of the electric power sector companies’ assets are concentrated in fixed assets, configuring real guarantees that can be used in indebtedness.
In
Table 3, the correlation matrix is presented, showing no strong correlations (above 0.8).
Table 4 presents the values for the four regression models, none of which showed a VIF exceeding 5. This led us to conclude that there is no presence of multicollinearity in the sample.
The next step was to apply the Chow test to choose between the pooled model and fixed effects (FE). The results for the four models are shown in
Table 5. According to the presented results, for all tested models, the fixed effects model was preferred over the pooled model.
Before performing the Hausman test (to choose between the fixed effects and random effects), it was necessary to identify the presence of heteroscedasticity and autocorrelation; if present, the robust Hausman test must be used.
Table 6 presents the results of the modified White test for panel data. Based on the results obtained, the null hypothesis of homoscedastic residuals was rejected for all models, demonstrating the presence of heteroscedasticity in the residuals of the generated models.
Table 7 shows the results of the Wooldridge test for panel data. The ROE models with C1 and C5 did not show indications of autocorrelation, and with a significance level of 10%, it was not possible to reject the null hypothesis of absence of autocorrelation for these models. In contrast, both ET models with C1 and C5 revealed autocorrelation in the residuals, rejecting the null hypothesis of absence of autocorrelation.
Considering the results from
Table 6 (heteroscedasticity tests) and
Table 7 (autocorrelation tests), which indicated the presence of heteroscedasticity in all models and autocorrelation in the ET models with C1 and C5, the robust Hausman test was conducted. This test aids in choosing between the fixed effects (FE) and random effects (RE) models. The results are displayed in
Table 8. For all proposed models, the random effects model was the most suitable, with a high level of significance (above 50% for all models).
Table 9 contains the results of the Breusch and Pagan test for selecting between the pooled model and RE. For all models, the test confirmed that the RE model fits the data best.
Regarding the stationarity tests, the results are presented in
Table 10. The tests were conducted without a trend, with deviation, without lags, and with the removal of cross-sectional means. As the results indicate, the series proved to be stationary, corroborating the statistical power of the findings.
In light of the results from the aforementioned tests, the model selected was the random effects model, estimated using FGLS to correct for the heteroscedasticity present in all models and the autocorrelation found in the ET models with C1 and C5. In essence, FGLS is a two-step process that “transforms” the model so that the errors become homoscedastic and uncorrelated; the mathematical explanation goes beyond the intentions of this work. The results of the models are presented in
Table A2 in
Appendix B.
In the ROE with C1 model, all variables were significant at a 0% level of significance. Notably, the C1 variable showed a negative relationship with ROE. An increase of 1% in ownership structure results in a decrease of −0.107% in return on equity. The DB variable presented a negative relationship (as expected), while the other variables were positive.
In the ROE with C5 model, all variables were significant at a 0% level of significance except for C5. This variable did not show statistical significance, with a p-value of 52.6%. This indicates that as a company’s capital becomes more dispersed, diversifying control, it is no longer statistically relevant for the performance measured by ROE. The signs and values of the other variables were similar to the ROE with C1 model, reinforcing the correct specification of the model.
For the ET with C1 model, all variables were significant at a 0% level of significance. The C1 variable showed a positive relationship with ET, indicating that as the ownership concentration represented by the control of the largest ordinary shareholder increases by 1%, ET increases by 0.095%, reflecting a deterioration in the company’s indebtedness indicator. RB and LL showed a negative relationship, meaning that as income and revenue increase, ET decreases. The other variables exhibited positive relationships as expected.
In the ET with C5 model, only the constant was not significant at the 10% level, while all other variables were significant at the 0% level. C5 remained significant, indicating that even with capital dispersion, ownership concentration continues to play a relevant role in the company’s indebtedness. This can be explained by the fact that as capital becomes more dispersed, it becomes increasingly difficult to exercise control over indebtedness; decisions regarding debt increases are made in a decentralized manner, showing a slight increase (0.103) compared to the C1 variable (0.095). The other variables showed similar values and signs to the ET with C1 model.
Returning to the research problem presented in the introduction: Does ownership structure influence the debt and efficiency of companies in the electricity sector? The answer to this question was yes. As verified by the results cited above, it can be stated that ownership structure influences the debt and efficiency of companies in the electricity sector. For efficiency, this relationship is negative, but as control is dissipated among a greater number of shareholders, this relationship ceases to exist, demonstrating an improvement in companies that are not concentrated. For debt, the relationship was positive and, despite the dispersion of capital, continues to exert influence. The results found in this study corroborate those found by [
11,
24,
25,
26]. The variables used in this study and by the aforementioned authors are similar, if not identical, allowing for comparison. These authors’ analysis focused on the global market, and this research focuses specifically on the electricity sector.
These results indicate potential implications such as a greater likelihood of expropriation of minority shareholders and less professionalization within the company, given the negative relationship found between the concentration of ownership structure and company efficiency. Greater monitoring guarantees may be necessary to prevent expropriation of minority shareholders, even if this increases costs. Improving internal company management, professionalizing key executives, can also contribute to improving these results. Industry regulators can develop policies that encourage competition and capital dissipation, given that greater capital dispersion has improved company performance. These characteristics confirm the results of the authors cited above, stating that the Brazilian market is developing, with room for maturity and efficiency gains with improvements in company ownership structures.
This research has some limitations, including the relatively small sample size and the lack of other sector-specific research for comparison [
40]. The results should be interpreted as indicators of the relevance and influence of ownership structure in the sector, encouraging the analysis of these structures as a complementary tool to corroborate company evaluations, but should not be interpreted as determinants of company results or substitutes for traditional indicator analyses.
5. Conclusions
This research aimed to identify the influence of ownership structure on the indebtedness and performance of companies in the electric sector. A panel data methodology was employed to acknowledge the heterogeneity of companies and to measure and identify the actual effects that ownership structure has. This study was innovative, highlighting its originality by measuring these effects specifically for the electric sector, with no similar studies identified for this area until now.
The findings were robust and satisfied various statistical tests, confirming the solidity of the presented numbers. Regarding company efficiency measured by ROE, the results indicated that concentrated ownership structure in the electric sector negatively affects the company’s performance (−0.107). As capital is dispersed, reducing control, the ownership structure ceases to be significant, emphasizing the importance that the largest shareholders exert on the company.
In relation to indebtedness, a positive relationship was found; as concentration increases (0.095), so does indebtedness. Even with control dilution, as measured by C5 (0.103), the ownership structure remains significant. This demonstrates that the ownership structure is relevant in relation to indebtedness; however, even with the dilution of control by the five largest ordinary shareholders, it continues to be significant, necessitating further dilution for the capital structure to cease influencing indebtedness. This could be particularly detrimental to minority shareholders who do not actively participate in decisions regarding company indebtedness.
This work contributes to the scientific literature by confirming that the ownership structure is an indicator to consider in the analysis of companies in the electric sector, as it can affect not only the company’s indebtedness but also its efficiency. This study provides an empirical foundation for a sector that had not been analyzed through this lens, given the relevance and importance of the research theme.
The practical implications of this research’s results lie in highlighting that ownership structure, which is not always considered in analyses, also influences company performance. Regulators can consider ownership structure when developing sectoral policies and use it as an indirect means to achieve their objectives, especially in competition policies and mergers of companies in the sector, considering that the results indicate that more concentrated companies are less efficient. Thus, ownership structure can serve as a vehicle for achieving certain policies. All stakeholders can benefit from these results, as the efficiency of electricity companies can help reduce dependence on fossil fuels.
For future research, studies are suggested that compare the ownership structure of the electricity sector in other countries, allowing the comparison of results from the same sector in different contexts.