**5. Discussion**

This report shows the large picture of leadership and innovation research in connection to and identifies directions for future research through a survey of 80 publications published between 2012 and the first half of 2022. It demonstrates that leadership is regarded as a key factor influencing green innovation and sustainable innovation (e.g., [100–102]) and that research in this area is expanding, with all the studies, we included in our study having been published within the past ten years. Our review also reveals that interest in innovation research is increasing, which is consistent with earlier research such as [103]. For instance, many academics have abandoned the idea of generic innovation. The huge rise in studies that began in 2018 reflects the progress that has been made in using a sustainable innovation study paradigm and offers remarkable actionable advice. An academic understanding of green innovation and sustainable innovation is necessary despite the recent emphasis on environmentally friendly methods by many academics.

The results show that Western nations have greater leadership, inventiveness, and green innovation than their developing counterparts. This suggests that academics from Asia are becoming more concerned with innovative work behavior and are concentrating more on reducing the negative effects of innovation performance. The results demonstrate that qualitative research predominates over other methods of research (i.e., qualitative, mixed method, and conceptual). Most quantitative analyses have traditionally employed surveys as a method of gathering data. To uncover and clarify novel concepts and phenomena, however, there appears to be an urgent need for qualitative, conceptual, or at least mixed-method research given the nascency of this topic. To theoretically support the indicated links (such as leadership-greeninnovation, sustainability, and innovativeness) and influence the future of the study domain, academics should concentrate on providing concepts, theories, and techniques [104]. Future efforts can focus on creating customized measures for the study domain to better capture the dyadic interaction. To investigate the potential

implications of leadership styles, scholars have chosen a variety of theories. For instance, the resource-based view has been used as the theoretical basis for responsible leadership studies to examine green transformational leadership [105], while the resource-based view has also been used to examine environmental leadership [106], and social exchange theory [102]. (e.g., [47]). Studies analyzing the connection between innovation and servant leadership have also referenced the conservation of resources hypothesis (e.g., [107]). These findings demonstrate the absence of a widely acknowledged theoretical framework that can support the link between leadership and green innovation. Future studies in the field of service research will be greatly influenced by this theoretical gap. Based on the primary conclusions of our study, we offer specific recommendations for further research in the fundamental areas below. We also provide potential research topics based on the three domains, which can encourage academics to carry out additional research in the field of service research.

### **5.1 Future research agenda**

#### *5.1.1 Research methods*

Even though all the studies in our sample were interested in causal effects, the majority of them were unsuitable for this goal due to poor study design and/or endogeneity problems. As a result, we offer the following methodological advice to guarantee that future studies carefully address causal issues.

First, longitudinal studies with adequate time lags should be preferred in the future to cross-sectional study approaches. According to the review's conclusions, case studies will be helpful because they will make it simpler to explain and enhance innovation performance in this relatively new subject. This is because case-study methodologies allow researchers to incorporate the opinions of industry practitioners and other experts. The bulk of earlier studies (38.7%) relied on survey techniques, which have constraints that make it unlikely that the findings will add to our conceptual knowledge of the service environment., there aren't many qualitative research techniques in the literature yet. Careful qualitative research can assist establish solid theoretical underpinnings for a research area in its infancy, leading to the creation of precise constructs that are appropriate for the field's unique qualities. Therefore, we support additional studies in this area. However, when it comes to research methodology, we support multilevel studies that look at leadership as a concept at the group or organizational level. Because leaders typically engage in behaviors that are addressed to individual employees rather than a group, and because followers working in the same department and/or organization tend to be more influenced by group-level or firm-level leadership, such research could advance knowledge of leadership in employee innovation practices, including employee green innovation and sustainable innovation [108, 109].

#### *5.1.2 Measurement scales*

This study discovered that lower-order determinants of innovation performance were not adequately addressed in the literature. For instance, the innovation scale initially created by Chen et al. [110] comprises four elements for each of the subdimensions of product innovation and process innovation. However, researchers looking into the connection between leadership and innovation have not made a distinction between these parts and have viewed the measurement of sustainable innovation as a single element. As a result, researchers who intended to study innovativeness

#### *Leadership and Sustainable Innovation: A Systematic Literature Review DOI: http://dx.doi.org/10.5772/intechopen.109150*

unintentionally evaluated product innovation, and vice versa. In this regard, the ramifications of our findings are rather obvious. Deeper tools are a must for a better knowledge of innovation and sustainable innovation performance, and future research must focus on the person, the process, and the product. The development of metrics to gauge the promotion of green ideas, evaluation of the effectiveness of green idea promotion, and assessment of how teams or individuals originate and implement green ideas are some possible future stages. With these new initiatives in place, it will be feasible to define the roots of sustainable development and green innovation, including in terms of leadership behavior.

#### *5.1.3 Leadership styles*

According to our review, effective leadership practices are strongly correlated with innovation and long-term innovation performance. Most of the study, however, has only looked at the effects of transformational leadership and transactional leadership on creativity, inventiveness, and innovative work behavior. As a result, attention is seldom given to how bad leadership practices can hinder innovation. Furthermore, it is uncertain which leadership philosophies are the best predictors of creativity and innovativeness due to the lack of analysis of the contributions of various leadership characteristics. Investigating the leadership traits that most effectively forecast green and sustainable innovation is thus necessary. For this, a focus on leadership styles will not be sufficient, thus future research must examine the effect of leaders' identities (including their personality, knowledge, and behaviors). Even if we only concentrate on leadership styles, our analysis reveals that the bulk of studies has concentrated on measuring leadership styles as a single construct (ignoring the different dimensions of the transformational, transactional, servant, and authentic leadership). The performance of green innovation and sustainable innovation should be examined in relation to the sub-components of leadership styles, as well as the dimensional effects of various styles, in order to overcome this deficiency.

However, we discovered that various academics have looked at well-known general leadership techniques and styles that can accurately predict both green innovation and sustainable innovation [111, 112]. However, there is a chance for scholars to assist the growth of theory and interdisciplinary study in the business management literature given the growing interest in leadership and green practices, such as innovation and sustainability. Researchers could start by creating a green-specific leadership strategy that supports the overall advancement of the sustainable business management field as a research discipline and moves it beyond its current reliance on theoretical frameworks from other fields, such as information sciences, behavioral sciences, psychology, and finance. Since an organization can be described by its leader, this would be a good place to start. Researchers might, for instance, create a new theory of green leadership that emphasizes ecologically responsible leadership practices in a company with an emphasis on defining the identity and traits of such a leader (in terms of, for example, personality and intelligence). Like, this leadership style might be explained in terms of the knowledge a green leader needs to have to run an organization effectively and efficiently. Finally, researchers could define the behaviors expected of green leaders, such as the specific management implications of their activities and how they support sustainable innovation. Future researchers are urged to quickly create this new theoretical approach considering the probable requirement for leadership.

The lack of clarity, particularly in terms of theory and causality, poses a threat to working based on multidimensional definitions of leadership, so future attempts to

develop appropriate scales that concentrate on the lower-order constructs of transformational leadership should take this into consideration. Ways to emphasize the connection between leadership styles and innovation (**Table 4**).


**Table 4.**

*Sample of the studies on leadership styles and innovation.*

*Leadership and Sustainable Innovation: A Systematic Literature Review DOI: http://dx.doi.org/10.5772/intechopen.109150*
