The results obtained from the analysis of the 75 companies are presented separately for each model. The exploratory robustness analysis is performed using the Multilayer Perceptron (MLP) method. Each stage makes a considerable contribution to a better understanding of how the dimensions of intellectual capital influence company performance.
3.1. Modern IC Model
From our sample, we identified several simple indicators that facilitate comparability across companies (
Table 3). This enabled the construction of a composite intellectual capital (IC) score through principal component analysis (PCA). The aggregated scores represent the predictors used in our model for the three dimensions of intellectual capital: human capital (CU), relational capital (CR), and structural capital (CS). These scores resulted from reducing the data volume of seven financial and non-financial indicators. If raw values from the financial statements had been used, there would have been a risk that indicators with very large values would dominate the analysis, even if they were not the most relevant. In addition, the interpretation of the model would have become more difficult, while its robustness would have been reduced.
One of the important methodological aspects of this study is the way in which the ESG indicators were constructed. Standardized ESG data are not systematically available for companies listed on the Bucharest Stock Exchange during the analyzed period, 2018–2023, which is a challenge frequently encountered in research on emerging markets (
Farooq, 2015;
Karyani & Perdiansyah, 2022). For this reason, we opted for the construction of proxy variables derived from publicly available financial statements and governance reports.
The environmental dimension (E) was calculated as the ratio of net investment cash flow to total assets. We consider that investment intensity indirectly reflects the company’s commitment to long-term development and responsible environmental practices. The social dimension (S) was measured through net profit per employee, an indicator that captures the value created per worker and is consistent with approaches in the intellectual capital literature regarding human capital efficiency (
Nadeem et al., 2019). The governance dimension (G) was represented by the general solvency ratio, as the literature confirms a positive relationship between ESG performance and corporate solvency, with financially stable companies tending to exhibit stronger governance practices (
Brogi et al., 2022;
Yu & Su, 2024).
The composite ESG score was calculated as the arithmetic mean of the three normalized sub-scores, in order to ensure a balanced contribution of each dimension: ESG = (E_normalized + S_normalized + G_normalized)/3.
To ensure a balanced representation of each variable’s contribution through the composite score, the selected indicators were standardized prior to applying principal component analysis (PCA). The price-to-earnings ratio (PER) is the ratio of market price to earnings per share, illustrating how the market is valued based on profitability. In contrast, Tobin’s Q (TQ), used in this study as the dependent variable, captures the relationship between market value and book value of assets, serving as an indicator of market performance.
Thus, the PER is used only as a complementary indicator to support the interpretation of market perception, while the core empirical analysis is based on TQ. Using SPSS, we focused on the simple indicators presented in
Table 4, derived from the financial data of companies listed on the Bucharest Stock Exchange, to construct a composite intellectual capital score through dimensionality reduction. A standardized score was used to ensure comparability over the 2018–2023 period.
We note that the first four components have values greater than one, and if we add them together, we get 72.785%, which means that the degree of explanation in the total variance is significant. This percentage is appropriate to serve as a premise in the process of establishing a composite IC score.
The rotated component matrix illustrated in
Table 5 provides evidence that the theoretical model functions as intended, namely that the four dimensions of intellectual capital (IC) are integrated into the model.
The Kaiser criterion identified four components consistent with the proposed model, each with eigenvalues greater than 1. Within Component 1, the highest loadings are associated with gross productivity (0.980) and net profit per employee (0.979). For our sample, these values establish human capital as the main differentiating factor and also illustrate the efficiency of human capital.
Consistency with relational capital is captured in Component 2, where the highest loadings are associated with the Price-to-Earnings Ratio (PER), at 0.664, and book value per share, at 0.600. These results demonstrate that the model incorporates information related to investor perception and the dimension associated with external relationships within intellectual capital.
The efficiency of structural capital is captured by return on assets within Component 3, with a loading of 0.944. The high value of this indicator suggests that companies use their available organizational resources efficiently.
The financial stability of companies and the existence of governance practices are reflected in the solvency ratio of 0.964 within Component 4. Companies recording high values for this indicator are largely self-financed and may be considered financially stable. Furthermore, we consider that these companies exhibit corporate governance practices and effectively integrate ESG factors.
The graphical representation in
Figure 2 below indicates that, if the elbow method is applied, the components with the highest values—1.950 and 1.133—could be retained. On the other hand, the Kaiser criterion identifies four components with eigenvalues greater than 1, which explain the variance.
The statistical results obtained for the four components demonstrate that the proposed conceptual model integrates and retains all four dimensions.
After processing the database for selected companies listed on the Bucharest Stock Exchange, we found that 99.9% of the variation in intellectual capital is explained by four variables: human capital, structural capital, relational capital, and sustainability indicators (ESG),
Table 6.
The very high value of the coefficient of determination should be interpreted with caution. The composite intellectual capital score is built from the same conceptual dimensions—human capital (CU), structural capital (CS), relational capital (CR), and ESG factors—that are subsequently used as explanatory variables in the regression model. Under these conditions, the high explanatory power largely reflects the structural relationship between the component variables and the resulting aggregate indicator, rather than representing an independent validation of the model. The near equality between R
2 and adjusted R
2 suggests strong internal consistency. The value of 73,734.013 for F Change and 0 for Sig. F. Change demonstrates that, from a statistical point of view, this model is highly significant. In this context, the value of intellectual capital, influenced by CU, CS, CR, and ESG, is much more significant and complex, and its variation is much easier to understand. The model created based on the four dimensions,
Table 7, is relevant, and the F test, where F = 73,734.013,
p < 0.001, demonstrates that it is based on a valid methodology and reasoning.
The ANOVA test results demonstrate that the model proposed in our research, based on the four dimensions, is globally significant, with an F value of 73,734 and a
p-value of less than 0.001. Additionally, the results show that the dimension that most influences IC is human capital, with 0.987. Its value is statistically significant (
p is less than 0.001), thus becoming the main determinant of intellectual capital. If we analyze the Unstandardized coefficient, we find that an increase in HC by a single unit will have the effect of increasing IC by 0.329 units (
Table 8). According to Collinearity Statistics, a high collinearity was established between the HC and ESG dimensions.
Looking at the results in
Table 8, we can observe that human capital has the strongest influence on the composite IC score (β = 0.987;
p < 0.001). An increase of one unit in human capital leads to an increase of 0.329 units in the intellectual capital score. We note that this result should be read carefully. The composite IC score is built from the same dimensions that are used as predictors in the regression, which means that part of this explanatory power reflects the structural relationship between the variables rather than an independent confirmation of the model. Additionally, the high multicollinearity between CU and ESG (VIF > 100) limits the reliability of individual coefficients. With these considerations in mind, we treat human capital as the most prominent dimension in our model, while acknowledging that the strength of this relationship is partly a consequence of the way the model was constructed.
The high VIF values for the human capital (103.584) and ESG (103.499) dimensions suggest a conceptual and methodological overlap between these two components. This situation may affect the stability of the coefficients in the combined model. To clarify the independent contribution of ESG factors, we ran a separate regression analysis. The independent variable is the ESG score alone, while the dependent variable is market performance measured by Tobin’s Q.
The results of this analysis confirm that ESG, analyzed independently, does not significantly explain the variation in market performance (R2 = 0.000; F = 0.162; p = 0.687). The standardized coefficient Beta = −0.019 is statistically insignificant (p = 0.687), and the VIF value of 1.000 confirms the absence of multicollinearity when ESG is analyzed separately from the other components.
Although we obtained high VIF values, above 100, for human capital (VIF = 103.584) and ESG (VIF = 103.499), the arguments for retaining the integrated model involve two essential aspects.
The first argument relates to the main objective of the model—assessing the aggregate explanatory power of the four intellectual capital dimensions on market performance, rather than estimating individual coefficients precisely. Multicollinearity limits the interpretation of individual coefficients, but does not affect the overall quality of the model. It is important to note that the model remains globally significant (F = 73,734.013, p < 0.001). Additionally, CS and CR present VIF values of 1.002 and 1.009, respectively. This shows that multicollinearity occurs strictly between CU and ESG, without affecting the other dimensions of the model.
The second argument relates to the conceptual overlap between CU and ESG. This reflects an empirical reality specific to emerging markets, where the proxy construction of ESG indicators inevitably shares variance with human capital indicators. Consequently, the interpretation of the combined model is conducted at the conceptual level, rather than through the lens of individual coefficients, while the distinct effect of ESG is assessed through a separate regression.
These results are consistent with the H0 hypothesis of the study. The analysis highlights that the identified limitation is not methodological in nature but rather reflects an empirical reality: in the context of the Romanian capital market, ESG factors constructed on the basis of publicly available data do not have significant independent explanatory power over the market value of listed companies. This conclusion opens important directions for future research, particularly regarding the availability and standardization of ESG data in emerging markets.
3.4. Exploratory MLP Analysis
The results show that high-quality human capital will have a positive effect on innovation, and companies will adapt much more easily to market trends (
Table 15).
This will implicitly increase the share price of companies listed on the BVB, in proportion to a higher market value. Our exploratory MLP analysis suggests that an increased value of HC may be associated with an increase in TQ, followed by the influence of relational capital with 92.1%, although these results should be interpreted with caution, given the exploratory nature of the analysis. This percentage confirms that employee relations are almost as important as human capital, especially for investors. The environmental, social, and governance factors have a positive impact on market value. Although IC or TQ values do not appear in the annual balance sheet, they are a defining element for value creation. To test the validity of the hypothesis that ESG has a significant influence on both IC and TQ, we applied an exploratory robustness analysis using the Multilayer Perceptron (MLP) model to illustrate the degree of importance of the four predictors and to capture the significance of sustainability factors. In this study, the model was applied to highlight the nonlinear relationships that emerge between company performance and the explanatory variables. This makes it much easier to highlight the indirect contribution these variables make to achieving high performance.
To assess the quality of the exploratory robustness analysis (MLP) and facilitate the comparison between the traditional and modern models,
Table 16 presents the performance indicators of the MLP for both the testing and training phases.
The results captured by the MLP also indicate high relative errors of 0.998 in the training phase and 0.994 in the testing phase. In our case, a value close to 1 suggests that the exploratory robustness analysis (MLP) does not adequately explain market performance measured through Tobin’s Q as the dependent variable. We acknowledge that a relative error of 0.998 reflects the difficulty of the MLP model in capturing market performance in this specific context. For this reason, we treat these results as exploratory, intended to illustrate the relative importance of predictors rather than to confirm the predictive accuracy of the model. Thus, we argue that there is a complex relationship between the dimensions of intellectual capital (IC) and the market value of the companies in our sample, which is influenced by external factors. One reason why market performance, through the dimensions CU, CS, CR, and ESG, is difficult to explain may be that the market of companies listed on the Romanian Stock Exchange does not sufficiently value intellectual capital. These results may also be considered a limitation of the proposed model, which could be addressed in future research by selecting a larger sample of companies.