| Linguistic Term | Fuzzy Number |
| Very Low | (0, 0, 0.2) |
| Low | (0, 0.2, 0.4) |
| Medium | (0.3, 0.5, 0.7) |
| High | (0.6, 0.8, 1) |
| Very High | (0.8, 1, 1) |
In recent years, there has been a rise in the significance of environmental, social, and governance (ESG) considerations when making investment decisions, suggesting a shift towards more moral and sustainable investing practices. The application of fuzzy logic (FL) in ESG investment decision-making is thoroughly examined in this review, which highlights FL's inherent capability to handle the subjectivity and uncertainty present in ESG data. We examine several FL approaches, such as fuzzy inference systems, fuzzy multi-criteria decision-making (MCDM), and FL-based grading models, and show how they contribute to a more adaptable and sophisticated assessment of corporate sustainability. This work presents a novel Hybrid Fuzzy-Neural Network (Fuzzy-NN) Model for advanced ESG analysis, building on these insights. In contrast to more conventional methods such as ANFIS, our model empirically validates the effectiveness and improved performance of this hybrid method in predicting financial outcomes using real NIFTY 50 time series financial data (2020-2024) with ESG details extrapolated from 2023-2024. The findings demonstrate how it can improve investment decisions by offering both reliable financial projections and easily comprehensible ESG evaluations. Lastly, we address relevant research gaps and suggest potential avenues for future work in the developing field of sustainable finance.
| Citation: |
Table 1. Fuzzy scale for likelihood and impact
| Linguistic Term | Fuzzy Number |
| Very Low | (0, 0, 0.2) |
| Low | (0, 0.2, 0.4) |
| Medium | (0.3, 0.5, 0.7) |
| High | (0.6, 0.8, 1) |
| Very High | (0.8, 1, 1) |
Table 2. Fuzzy ESG Score Statistics by Sector
| Sector | Median FIS ESG Score | Interquartile Range (IQR) | Number of Companies |
| Energy | 68.50 | 10.20 | 15 |
| Industrials | 62.10 | 15.50 | 12 |
| Healthcare | 75.30 | 8.00 | 10 |
| Basic Materials | 55.80 | 7.50 | 8 |
| Financial Services | 70.90 | 12.30 | 20 |
| Consumer Cyclical | 61.20 | 11.80 | 15 |
| Communication Services | 58.70 | 9.10 | 7 |
| Consumer Defensive | 65.40 | 6.20 | 9 |
| Technology | 78.10 | 5.00 | 18 |
| Utilities | 52.60 | 4.50 | 14 |
| [1] |
H. Al Zaabi and H. Bashir, Modeling and analyzing project interdependencies in project portfolios using an integrated social network analysis-fuzzy TOPSIS MICMAC approach, International Journal of System Assurance Engineering and Management, 11 (2020), 1083-1106.
doi: 10.1007/s13198-020-00962-3.
|
| [2] |
R. Alshahrani, M. Yenugula, H. Algethami, F. Alharbi, S. S. Goswami, Q. N. Naveed, A. Lasisi, S. Islam, N. A. Khan and S. Zahmatkesh, Establishing the fuzzy integrated hybrid MCDM framework to identify the key barriers to implementing artificial intelligence-enabled sustainable cloud system in an IT industry, Expert Systems with Applications, 238 (2024), 121732.
doi: 10.1016/j.eswa.2023.121732.
|
| [3] |
M. Anokhina, A. Kolesnikov and M. Maksimov, Cognitive model of the ESG transformation of the organization, E3S Web of Conferences, 403 (2023), 08032.
doi: 10.1051/e3sconf/202340308032.
|
| [4] |
A. Azadeh, M. Zarrin, M. Abdollahi, S. Noury and S. Farahmand, Leanness assessment and optimization by fuzzy cognitive map and multivariate analysis, Expert Systems with Applications, 42 (2015), 6050-6064.
doi: 10.1016/j.eswa.2015.04.007.
|
| [5] |
C. Bai, S. Kusi-Sarpong, H. B. Ahmadi and J. Sarkis, Social sustainable supplier evaluation and selection: a group decision-support approach, International Journal of Production Research, 57 (2019), 7046-7067.
doi: 10.1080/00207543.2019.1574042.
|
| [6] |
I. Bak and K. Cheba, ESG risk as a new challenge for financial markets, Finance and Sustainable Development, Routledge, (2020), 21-39.
doi: 10.4324/9781003011132-3.
|
| [7] |
L. Batra and H. Taneja, Approximate-analytical solution to the information measure's based quanto option pricing model, Chaos, Solitons and Fractals, 153 (2021), 111493.
doi: 10.1016/j.chaos.2021.111493.
|
| [8] |
L. Batra and H. Taneja, Comparison between information theoretic measures to assess financial markets, FinTech, 1 (2022), 137-154.
doi: 10.3390/fintech1020011.
|
| [9] |
F. Berg, J. F. Koelbel and R. Rigobon, Aggregate confusion: The divergence of ESG ratings, Review of Finance, 26 (2022), 1315-1344.
doi: 10.1093/rof/rfac033.
|
| [10] |
A. Bilbao-Terol, M. Arenas-Parra and V. Cañal-Fernández, Selection of socially responsible portfolios using goal programming and fuzzy technology, Information Sciences, 189 (2012), 110-125.
doi: 10.1016/j.ins.2011.12.001.
|
| [11] |
A. J. Brogan and S. Stidham Jr, Non-separation in the mean–lower-partial-moment portfolio optimization problem, European Journal of Operational Research, 184 (2008), 701-710.
doi: 10.1016/j.ejor.2006.11.028.
|
| [12] |
A. Buallay, Is sustainability reporting (ESG) associated with performance? evidence from the european banking sector, Management of Environmental Quality: An International Journal, 30 (2019), 98-115.
doi: 10.1108/MEQ-12-2017-0149.
|
| [13] |
C. Calvo, C. Ivorra and V. Liern, Fuzzy portfolio selection with non-financial goals: Exploring the efficient frontier, Annals of Operations Research, 245 (2016), 31-46.
doi: 10.1007/s10479-014-1561-2.
|
| [14] |
C. T. Chen, W. Z. Hung, K. H. Lin and H. L. Cheng, An evaluation model of service quality by applying linguistic TOPSIS method, IEEE/INFORMS International Conference on Service Operations, Logistics and Informatics, (2009), 335-340.
|
| [15] |
Y. Chen, S. Wang, J. Yao, Y. Li and S. Yang, Socially responsible supplier selection and sustainable supply chain development: A combined approach of total interpretive structural modeling and fuzzy analytic network process, Business Strategy and the Environment, 27 (2018), 1708-1719.
doi: 10.1002/bse.2236.
|
| [16] |
M. A. F. Chowdhury, M. Abdullah, M. A. K. Azad, Z. Sulong and M. N. Islam, Environmental, social and governance (ESG) rating prediction using machine learning approaches, Annals of Operations Research, (2023), 1-25.
doi: 10.1007/s10479-023-05633-7.
|
| [17] |
A. M. G. Cornelissen, The Two Faces of Sustainability: Fuzzy Evaluation of Sustainable Development, Wageningen University and Research, 2003.
|
| [18] |
B. De Schuymer, H. De Meyer and B. De Baets, A fuzzy approach to stochastic dominance of random variables, International Fuzzy Systems Association World Congress, (2003), 253-260.
doi: 10.1007/3-540-44967-1_30.
|
| [19] |
R. G. Eccles and S. Klimenko, The investor revolution, Harvard Business Review, 97 (2019), 106-116.
|
| [20] |
A. Eghtesad and E. Mohammadi, Portfolio optimization under ambiguity aversion using deep learning, machine learning, and time series, Journal of Financial Data Science, 6 (2024).
doi: 10.3905/jfds.2024.1.150.
|
| [21] |
E. Escrig-Olmedo, J. M. Rivera-Lirio, M. J. Muñoz-Torres and M. Á. Fernández-Izquierdo, Integrating multiple ESG investors' preferences into sustainable investment: A fuzzy multicriteria methodological approach, Journal of Cleaner Production, 162 (2017), 1334-1345.
doi: 10.1016/j.jclepro.2017.06.143.
|
| [22] |
B. Z. Filipiak, Fuzzy logic in business ethics, Fuzzy Business Models and ESG Risk: Offering a Sustainable Perspective on Companies and Financial Institutions, Springer, (2023), 73-104.
doi: 10.1007/978-3-031-40575-4_5.
|
| [23] |
M. M. Fouladgar, A. Yazdani-Chamzini, E. K. Zavadskas, S. H. Yakhchali and M. H. Ghasempourabadi, Project portfolio selection using fuzzy AHP and VIKOR techniques, Transformations in Business & Economics, 11 (2012).
|
| [24] |
M. R. Galankashi, F. M. Rafiei and M. Ghezelbash, Portfolio selection: A fuzzy-ANP approach, Financial Innovation, 6 (2020), 17.
doi: 10.1186/s40854-020-00175-4.
|
| [25] |
F. García, J. González-Bueno, J. Oliver and N. Riley, Selecting socially responsible portfolios: A fuzzy multicriteria approach, Sustainability, 11 (2019), 2496.
doi: 10.3390/su11092496.
|
| [26] |
S. M. Gasser, M. Rammerstorfer and K. Weinmayer, Markowitz revisited: Social portfolio engineering, European Journal of Operational Research, 258 (2017), 1181-1190.
doi: 10.1016/j.ejor.2016.10.043.
|
| [27] |
F. Gökgöz and M. E. Atmaca, Portfolio optimization under lower partial moments in emerging electricity markets: Evidence from turkey, Renewable and Sustainable Energy Reviews, 67 (2017), 437-449.
doi: 10.1016/j.rser.2016.09.029.
|
| [28] |
X. Gu, P. Angelov, J. Han and Q. Shen, Multilayer evolving fuzzy neural networks, IEEE Transactions on Fuzzy Systems, 31 (2023), 4158-4169.
doi: 10.1109/TFUZZ.2023.3276263.
|
| [29] |
L. X. Guo, C. C. Lin, P. F. Huang, S. Y. Jhou, S. C. Chen and F. S. Tsai, Fuzzy logic analysis for key factors for customer loyalty in e-shopping environment, Frontiers in Psychology, 12 (2021), 742699.
doi: 10.3389/fpsyg.2021.742699.
|
| [30] |
A. Gupta, Evaluating the Factors Affecting the Selection of Sustainable Public Transport System based on an Integrated AHP and Fuzzy TOPSIS Approach, Revitalization of Business Strategy in Emerging Economies, DPPG, BK School of Professional and Management, (2020).
|
| [31] |
P. D. Hoang, L. T. Nguyen and B. Q. Tran, Assessing environmental, social and governance (ESG) performance of global electronics industry: An integrated MCDM approach-based spherical fuzzy sets, Cogent Engineering, 11 (2024).
|
| [32] |
M. B. Jahromi, S. Kamalzadeh and H. Tajik, Portfolio optimization using a combined model of fuzzy network analytic process: An approach based on similarity and genetic algorithm, International Journal of Economics and Finance, 7 (2015).
|
| [33] |
J. Jin and Q. Han, ESG and corporate financial performance: The moderating role of corporate governance, Sustainability, 16 (2024), 218.
|
| [34] |
Y. Jin and J. Yan, Sustainable investing with ESG ambiguous information, Economics Letters, 241 (2024), 111796.
doi: 10.1016/j.econlet.2024.111796.
|
| [35] |
S. Kheybari, F. M. Rezaie and H. Farazmand, Analytic network process: An overview of applications, Applied Mathematics and Computation, 367 (2020), 124780.
doi: 10.1016/j.amc.2019.124780.
|
| [36] |
M. Khoshfarman Borji, A. R. Sayadi and E. Nikbakhsh, A novel sustainable multi-objective optimization model for steel supply chain design considering technical and managerial issues: A case study, Journal of Mining and Environment, 14 (2023), 295-319.
|
| [37] |
B. Kim, J. Kim and J. Kim, Evaluation model for investment in solar photovoltaic power generation using fuzzy analytic hierarchy process, Sustainability, 11 (2019), 2905.
doi: 10.3390/su11102905.
|
| [38] |
B. Kitchenham, R. Pretorius, D. Budgen, O. P. Brereton, M. Turner, M. Niazi and S. Linkman, Systematic literature reviews in software engineering–a tertiary study, Information and Software Technology, 52 (2010), 792-805.
doi: 10.1016/j.infsof.2010.03.006.
|
| [39] |
S. Kotsantonis and G. Serafeim, Four things no one will tell you about ESG data, Journal of Applied Corporate Finance, 31 (2019), 50-58.
doi: 10.1111/jacf.12346.
|
| [40] |
O. Lagodiyenko, V. Lagodiienko, L. Ivanchenkova, I. Romanashenko and O. Laskaiev, Prospects for the development of the esg concept in the face of new challenges, Collection Of Papers New Economy, 2023 (2023), 179.
|
| [41] |
H. Li, H. Guo, X. Hao and X. Zhang, The ESG rating, spillover of ESG ratings, and stock return: Evidence from chinese listed firms, Pacific-Basin Finance Journal, 80 (2023), 102091.
doi: 10.1016/j.pacfin.2023.102091.
|
| [42] |
X. Li, F. Xu and K. Jing, Robust enhanced indexation with ESG: An empirical study in the chinese stock market, Economic Modelling, 107 (2022), 105711.
doi: 10.1016/j.econmod.2021.105711.
|
| [43] |
H.-W. Lo and S.-W. Lin, Identifying ESG investment key indicators and selecting investment trust companies by using a z-fuzzy-based decision-making model, Socio-Economic Planning Sciences, 90 (2023), 101759.
doi: 10.1016/j.seps.2023.101759.
|
| [44] |
R. Lochab and V. Kumar, A new reconstruction of numerical fluxes for conservation laws using fuzzy operators, International Journal for Numerical Methods in Fluids, 93 (2021), 1690-1711.
doi: 10.1002/fld.4948.
|
| [45] |
R. Lochab and V. Kumar, An improved flux limiter using fuzzy modifiers for hyperbolic conservation laws, Mathematics and Computers in Simulation, 181 (2021), 16-37.
doi: 10.1016/j.matcom.2020.09.012.
|
| [46] |
R. Lochab and V. Kumar, Numerical simulation of hyperbolic conservation laws using high resolution schemes with the indulgence of fuzzy logic, Lecture Notes in Computer Science, Springer, Cham., 11974 (2020), 139-153.
doi: 10.1007/978-3-030-40616-5_11.
|
| [47] |
D. Luo, J. Yan and Q. Yan, The duality of ESG: Impact of ratings and disagreement on stock crash risk in China, Finance Research Letters, 58 (2023), 104479.
doi: 10.1016/j.frl.2023.104479.
|
| [48] |
Y. Luo, H. Wang and P. Xie, ESG performance and corporate innovation: Evidence from China, Finance Research Letters, 56 (2023), 103798.
|
| [49] |
J. M. Mendel, Type-1 fuzzy sets and fuzzy logic, Explainable Uncertain Rule-Based Fuzzy Systems, (2024), 17-73.
doi: 10.1007/978-3-031-35378-9_2.
|
| [50] |
X. Meng and G. M. Shaikh, Evaluating environmental, social, and governance criteria and green finance investment strategies using fuzzy AHP and fuzzy WASPAS, Sustainability, 15 (2023), 6786.
doi: 10.3390/su15086786.
|
| [51] |
A. K. Mishra, R. Kumar and D. P. Bal, ESG volatility prediction using GARCH and LSTM models, Financial Internet Quarterly, 19 (2023), 97-114.
doi: 10.2478/fiqf-2023-0029.
|
| [52] |
P. H. Nguyen, L. A. T. Nguyen, H. A. T. Pham and M. A. T. Pham, Breaking ground in ESG assessment: Integrated DEA and MCDM framework with spherical fuzzy sets for Vietnam's wire and cable sector, Journal of Open Innovation: Technology, Market, and Complexity, 9 (2023), 100136.
doi: 10.1016/j.joitmc.2023.100136.
|
| [53] |
A. Paat, J. Majak, V. Karu and M. Hitch, Fuzzy analytical hierarchy process based environmental, social and governance risks assessment for the future phosphorite mining in Estonia, The Extractive Industries and Society, 17 (2024), 101438.
doi: 10.1016/j.exis.2024.101438.
|
| [54] |
M. Pislaru, I. V. Herghiligiu and I.-B. Robu, Corporate sustainable performance assessment based on fuzzy logic, Journal of Cleaner Production, 223 (2019), 998-1013.
doi: 10.1016/j.jclepro.2019.03.130.
|
| [55] |
E. Pourjavad and A. Shahin, The application of mamdani fuzzy inference system in evaluating green supply chain management performance, International Journal of Fuzzy Systems, 20 (2018), 901-912.
doi: 10.1007/s40815-017-0378-y.
|
| [56] |
R. Raei and M. Jahromi, Portfolio optimization using a hybrid of fuzzy ANP, VIKOR and TOPSIS, Management Science Letters, 2 (2012), 2473-2484.
doi: 10.5267/j.msl.2012.07.019.
|
| [57] |
S. Rajak and S. Vinodh, Application of fuzzy logic for social sustainability performance evaluation: A case study of an Indian automotive component manufacturing organization, Journal of Cleaner Production, 108 (2015), 1184-1192.
doi: 10.1016/j.jclepro.2015.05.070.
|
| [58] |
M. Rasoulzadeh, S. A. Edalatpanah, M. Fallah and S. E. Najafi, A hybrid model for choosing the optimal stock portfolio under intuitionistic fuzzy sets, Iranian Journal of Fuzzy Systems, 21 (2) (2024), 161-179.
|
| [59] |
P. R. Rau and T. Yu, A survey on ESG: Investors, institutions and firms, China Finance Review International, 14 (2024), 3-33.
doi: 10.1108/CFRI-12-2022-0260.
|
| [60] |
J. Reig-Mullor, A. Garcia-Bernabeu, D. Pla-Santamaria and M. Vercher-Ferrandiz, Evaluating ESG corporate performance using a new neutrosophic AHP-TOPSIS based approach, Technological and Economic Development of Economy, 28 (5) (2022), 1242-1266.
doi: 10.3846/tede.2022.17004.
|
| [61] |
P. K. Roy, Enriching the green economy through sustainable investments: An ESG-based credit rating model for green financing, Journal of Cleaner Production, 420 (2023), 138315.
doi: 10.1016/j.jclepro.2023.138315.
|
| [62] |
M. Sahamkhadam and A. Stephan, Socially responsible multiobjective optimal portfolios, Journal of the Operational Research Society, (2024), 1-12.
|
| [63] |
P. Seele, Digitally unified reporting: How XBRL-based real-time transparency helps in combining integrated sustainability reporting and performance control, Journal of Cleaner Production, 136 (2016), 65-77.
doi: 10.1016/j.jclepro.2016.01.102.
|
| [64] |
S. Senfi, R. Sheikh and S. S. Sana, A portfolio selection using the intuitionistic fuzzy analytic hierarchy process: A case study of the tehran stock exchange, Green Finance, 6 (2024), 219-248.
doi: 10.3934/GF.2024009.
|
| [65] |
R. B. Shepard, Quantifying Environmental Impact Assessments Using Fuzzy Logic, Springer, 2005.
|
| [66] |
S. Škápa, N. Bočková, K. Doubravský and M. Dohnal, Fuzzy confrontations of models of ESG investing versus non-ESG investing based on artificial intelligence algorithms, Journal of Sustainable Finance & Investment, 13 (2023), 763-775.
|
| [67] |
K. Sood, P. Pathak, J. Jain and S. Gupta, How does an investor prioritize ESG factors in India? an assessment based on fuzzy AHP, Managerial Finance, 49 (2023), 66-87.
doi: 10.1108/MF-04-2022-0162.
|
| [68] |
J. Su and Y. Sun, An improved TOPSIS model based on cumulative prospect theory: Application to ESG performance evaluation of state-owned mining enterprises, Sustainability, 15 (2023), 10046.
doi: 10.3390/su151310046.
|
| [69] |
M. G. Tadesse, E. Loghin, M. Pislaru, L. Wang, Y. Chen, V. Nierstrasz and C. Loghin, Prediction of the tactile comfort of fabrics from functional finishing parameters using fuzzy logic and artificial neural network models, Textile Research Journal, 89 (2019), 4083-4094.
doi: 10.1177/0040517519829008.
|
| [70] |
M. Taleb and H. J. Kadhum, The role of artificial intelligence in promoting the environmental, social and governance (ESG) practices, International Conference on Explainable Artificial Intelligence in the Digital Sustainability, (2024), 256-279.
doi: 10.1007/978-3-031-63717-9_17.
|
| [71] |
S. Tesfamariam and R. Sadiq, Risk-based environmental decision-making using fuzzy analytic hierarchy process (F-AHP), Stochastic Environmental Research and Risk Assessment, 21 (2006), 35-50.
doi: 10.1007/s00477-006-0042-9.
|
| [72] |
H. Wang, S. Bhattacharjee, N. Kausar, A. Mohammadzadeh, D. Pamucar and N. A. D. Ide, Financial performance assessment by a Type-2 fuzzy logic approach, Mathematical Problems in Engineering, 2023 (2023), 5926162.
doi: 10.1155/2023/5926162.
|
| [73] |
L.-H. Wu, L. Wu, J. Shi and Y.-T. Chou, Project portfolio selection considering uncertainty: Stochastic dominance-based fuzzy ranking, International Journal of Fuzzy Systems, 2021 (2021), 1-19.
|
| [74] |
Q. Wu, X. Liu, J. Qin, L. Zhou, A. Mardani and M. Deveci, An integrated multi-criteria decision-making and multi-objective optimization model for socially responsible portfolio selection, Technological Forecasting and Social Change, 184 (2022), 121977.
doi: 10.1016/j.techfore.2022.121977.
|
| [75] |
K. Yu, Q. Wu, X. Chen, W. Wang and A. Mardani, An integrated MCDM framework for evaluating the environmental, social, and governance (ESG) sustainable business performance, Annals of Operations Research, (2023), 1-32.
|
| [76] |
L. A. Zadeh, Fuzzy logic-a personal perspective, Fuzzy Sets and Systems, 281 (2015), 4-20.
doi: 10.1016/j.fss.2015.05.009.
|
| [77] |
A. Zebda, The problem of ambiguity and vagueness in accounting, Behavioral Research in Accounting, 3 (1991).
|
| [78] |
X. Zhou, Fuzzy analytical network process implementation with matlab, MATLAB-A fundamental Tool for Scientific Computing and Engineering Applications, 3 (2012), 133-160.
|
| [79] |
J. Zou, J. Yan and G. Deng, ESG rating confusion and bond spreads, Economic Modelling, 129 (2023), 106555.
doi: 10.1016/j.econmod.2023.106555.
|
Membership functions for input variables and output ESG score
Numerical results of ANFIS, and the Hybrid Fuzzy-NN Model based on NIFTY 50 data
Fuzzy ESG score distribution on the basis of various sectors