Network Leadership Theory: A New Research Agenda

As a social phenomenon and a mechanism for influencing others, leadership always has interested scientists. Literary reviews on the theoretical foundations, types of classifications, and prospects for leadership development are an essential element of careful study of this concept. Today, the systematization of types of leadership on various grounds is a necessary component for understanding the nature of this phenomenon. The paper analyzes 2,000 published research papers from the Scopus database, identifying critical terms related to leadership. Establishing links between leadership and related concepts creates the most accurate picture for further research on this topic. The study is devoted to studying the theoretical and practical experience of scientists worldwide who research management as a critical aspect in building an effective organization. Systematization of such data is the basis for identifying current and fundamentally new directions of effective leadership. The keyword in the described bibliometric analysis was the concept of “leadership”. New clusters have been formed with the most influential definitions of transformational leadership, communication, and shared leadership. The combination of quantitative and qualitative research methods determined the future directions of study in the further search for effective leadership tools. The content analysis of the most cited scientific works was carried out in the research, which reveals the essence of tools for the development of effective leadership and the need for timely diagnosis of the negative behavior of managers. Bibliometric analysis and analysis of the development of leadership theory reveal the need to implement the principles of Network Leadership Theory in modern organizations, which are the basis of the state's economic development as a whole.


Introduction
The leadership phenomenon keeps fascinating scholars and practitioners all around the world. The number of papers in the field increases, and new types of leadership appear. This trend relates to the changes in the socio-economic systems, which lead to constant changes in management processes. Leadership is a key component in the economic and social processes of any system, whether it is an organization, state, or a small business. The effectiveness of any unit depends on leaders who unite tangible and intangible resources with measurable processes, leading the team to expected outcomes. Network leadership is a promising direction in management studies as this system allows to achieve the anticipated results and build a lean organization. This approach to management requires more careful research and understanding of the tools for its implementation.

Literature Review
The study reflects the data from bibliometric analysis of 2000 scientific publications indexed by the Scopus database during 2017-2021. The most cited papers of scientists who have studied the concept of leadership from different points of view became the background of current research. Various forms of leadership have been studied: inspirational leadership (

Methodology and Research Methods
The tool for bibliometric analysis VOSviewer is used in the article. It helps select 2,000 scientific publications from the Scopus database using the keyword "leadership" for the period 2017-2021. As a result, there were seven formed clusters that are related to "leadership". Using VOSviewer, three visualizations were created. Network visualization shows links between a key concept and related categories. Overlay visualization shows the density of relationships between concepts. The Density visualization scheme reveals the most researched concepts and categories that need further study. The content analysis of the evolution of terms in the research field was based on the 20 most cited scientific papers on the proposed topic, and the areas for future research were identified.

Results
Two thousand scientific publications indexed by the Scopus database during 2017-2021 were selected to study the theoretical principles of the concept of "leadership" using the basic search with keywords (titles, abstracts). Based on the bibliometric analysis results of current scientific publications indexed by the Scopus database in 2017-2021 using the VOSviewer toolkit, a thesaurus (38 terms) was visualized to determine the link between the concept of "leadership" and related categories. Seven clusters marked in green, red, yellow, blue, turquoise, purple and orange were identified. Selected clusters can be named Leadership Style (red), Organizational Management (green), Ad Hoc Leadership (blue), Paternalistic & Authoritarian Leadership (yellow), Network Leadership Theory (purple), Strategic Management (turquoise), Opportunistic Leadership Behavior/Abusive Leadership (orange).
The results of bibliometric analysis, namely Network visualization between the key concept and the related categories, are presented in Fig. 1. If the frequency of mentioning a particular concept as a keyword increase, it reflects on the size in the circle's diameter, as is shown in Fig. 1. Cluster 1. Leadership Style consists of concepts defining the behavior of the leader with subordinates. The specific nature of this cluster is that the study of issues related to leadership style is a key element in management in the formation of a competitive organization. Transformational leadership is the most often mentioned term while studying the phenomenon of leadership. Cluster 2. Organizational Management includes the keywords "leadership", and "leadership development", besides others. Over some time, the study of basic concepts provides a complete picture of leadership theory development. This cluster includes such blocks as, Employee, Leadership, Leadership Development, Management, Motivation, Organization, Organization and Management, Total Quality Management. The most exploratory concept is related to the study of organizations where it is conducted.
Cluster 3. Ad hoc Leadership covers issues related to follow-up leadership. Socio-psychological methods of the leader's influence on subordinates are described. Meta-analysis of the concepts of Critical, Ethical, Servant, and Spiritual leadership allows us to conclude that the manager needs to implement these methods working with a team.
Communication is a central concept in Cluster 4. Paternalistic & Authoritarian Leadership. It is interesting fact that this cluster unites paternalistic and authoritarian leadership, the connection between them is needed to be discussed further. Above that, there is a link between mentioned and communications in the organization, and leader-member exchange.
Cluster 5. Network Leadership Theory examines areas related to the principles of Distributed leadership, Empowering leadership, Instructional leadership, Shared leadership. According to the current bibliometric analysis, the Network Leadership Theory has not been sufficiently studied. The Shared leadership block is marked on the diagram with the circle with the largest diameter, i.e., it is most often mentioned next to the key concept "leadership".  The next stage of the study is Density Visualization of the concept "leadership" and its links with other categories. Figure 3 shows the results of that visualization. The diagram shows two colors indicating the density of connections between the concepts − yellow and green. The brightest yellow circle around leadership, transformational leadership, and ethical leadership indicates the research intensity on these topics. Then the color becomes duller, which means a decrease in the number of studies related to these categories, such as Communication, Shared Leadership, Strategic Leadership, Abusive Supervision. Thus, clusters with dull colors contain concepts that need future research. In our opinion, the most relevant issues today relate to Network Leadership Theory. It is due to the fact that economic phenomena in developing countries need leaders who are focused on the social component of the organization such as team, staff, followers.

Conclusions
Based on the bibliometric and content analysis results and considering the principles of Network Leadership Theory, we can state that it is a promising area in the further development of management science. Network leadership aims to develop the potential of staff. The leader's focus on human resources ensures the efficient operation of the enterprise and makes it competitive. The formation of responsibility in each team member develops competent and influential followers. The presented research shows that the issues of Network Leadership Theory are insufficiently studied. However, there is a need for a more in-depth analysis of the mechanisms and tools for implementing the Network Leadership Theory. Since there are different areas of activity that have their properties and are fundamentally different from specific tasks and features in management, there is a need for a clear understanding of how the principles of Network Leadership Theory will be practical.