## 4 Research Clusters: Content Analysis
### Cluster 1: Sustainable Green Shipping Practices and Research
#### 4.1.1 Subcluster 1: Conceptualization and Theoretical Integration  
The first subcluster is identified as conceptualization and theoretical integration in the green shipping corridors research domain. Two articles focus on establishing a conceptual foundation and integrating relevant theories to explain sustainable practices. These works outline the antecedents and frameworks that guide sustainable or green shipping initiatives.  
[PERSON] et al. (2017) employ a Structural Equation Model to stakeholder theory, planned behavior theory, and resource dependence theory in order to examine sustainable shipping practices via survey data from 186 shipping companies [44]. The structural model confirms that stakeholder pressure, attitude, and behavioral control significantly drive the adoption of sustainable practices, directly and indirectly enhancing business performance. All hypothesized relationships (H1-H7) are positive and statistically significant at a 95% confidence level. The following hypotheses are: (1) H1. Stakeholder pressure has a positive effect on sustainable shipping practices; (2) H2. Sustainable shipping practices have a positive effect on shipping companies' business performance; (3) H3. Shipping companies' attitude towards sustainability has a positive effect on sustainable shipping practices; (4) H4. Shipping companies' perceived behavioral control of sustainability has a positive effect on sustainable shipping practices; (5) H5. Stakeholder pressure has a positive effect on shipping companies' attitude towards sustainability; (6) H6. Stakeholder pressure has a positive effect on shipping companies' perceived behavioral control of sustainability; and (7) Stakeholder pressure has a positive effect on shipping companies' business performance. By examining drivers, practices, and performance in a triadic framework, the study demonstrates that stakeholder pressure influences business performance both directly and indirectly through its effects on shipping companies' attitudes and behavioral control. Additionally, (1) bulk shipping companies experience greater stakeholder pressure compared to container shipping companies and (2) larger firms are more proactive in adopting these practices.  
[PERSON] et al. (2011) highlight increasing stakeholder awareness of environmental impacts from cargo movement, noting that shipping activities contribute to pollution, waste, and resource depletion [46]. The scholars outline the following six dimensions of green shipping practices (GSPs): (1) Company Policy and Procedure, (2) Shipping Documentation, (3) Shipping Equipment, (4) Shipper Cooperation, (5) Shipping Materials, and (6) Shipping Design and Compliance. Effective GSP adoption requires strong corporate commitment, cross-functional integration, and technological innovations, such as eco-friendly equipment and optimized voyage planning. Furthermore, institutional theory, which incorporates coercive, mimetic, and normative pressures, better explains GSP adoption than stakeholder theory. Enforced environmental regulations, industry norms, and customer demands drive firms toward the dual benefits of improved environmental performance and enhanced productivity.  
Key considerations in this subcluster include considering how institutional theory and behavioral models inform sustainable practices and the processes involved in conceptualizing and adopting green shipping practices.