**3. Leadership theory and styles**

Leadership has been defined in several ways. One definition is leadership is a process by which a person has influence over others to accomplish an objective and directs an organization that makes it more cohesive and coherent [10]. Another definition is leadership is a process by which an individual influences a group of others to achieve a common goal [11]. These definitions are describing "process leadership" which is the process of leaders applying their leadership knowledge and skills to situations. Leadership is learned, but it is influenced by leaders' beliefs, values, ethics, and character [12].

It is important that the effects of leadership are sustainable. Sustainable leadership has the following characteristics: sustainable leadership 1) creates opportunities for training and learning, 2) ensures success over time, 3) maintains the leadership of others, 4) develops human resources, and 5) develops diversity and capacity [13]. Sustainable leadership is often characterized by distributive leadership throughout an organization [14]. Successful leaders facilitate people's learning from other's diverse practices. Other's practices and approaches may be enlightening and informative [15].

Several theories have been postulated concerning leadership. Bass' Theory of Leadership states: a) personality traits lead people into leadership roles, b) events cause people to rise to the occasion, c) people can choose become leaders, and d) people can learn leadership skills [16]. Behavioral theories have stressed the role of how leaders' behavior impact their effectiveness and followers [17]. Behavioral leadership theory styles are autocratic, democratic, and laissez-faire. Behavioral theory states that leaders adopt one of these styles and that leaders are made and not born [18]. Contingency theory suggests that a leader' behavior is dependent on the situation. This theory is based on the proposition that successful leaders must align their approach to the specific situation, and there is no one optimal approach to leadership [19].

Transactional leadership theory states that a two-way relationship between a leader and followers is essential in meeting success. This theory is based on rewards and incentives for followers [20]. The servant leadership theory suggests that leaders serve first, then lead. The theory advocates patience, kindness, humility, respectfulness, honesty, and commitment. Following this theory, the leader must overcome self-interest to serve others [21]. Dominant leadership theory posits influencing others by being assertive and using one's power and formal authority [22]. Research has shown that dominant leaders are preferred in times of uncertainty. This is based on the assumption that dominant leaders are decisive and action oriented [23].

There are two major leadership styles, directive and participative. Directive leadership style involves giving clear directions, expectations, and objectives to followers. This style is most effective when a situation is complex, novel, or unexpected. Leaders using the directive style making decisions independent of input from subordinates [24]. Using this style leaders have a tendency to control discussions, dominate interactions, and direct tasks to their completion [25]. Directive leaders motivate subordinates to act to support the leader's strategy to address situations [26]. A result of directive leadership is achievement of high

levels of performance by providing clear goals [27]. Directive leadership has shown to improve exchange and processing of knowledge, which is another result for performance improvement [28].

Participative leadership is the process of jointly making decisions by a leader and subordinates [29]. The focus of this leadership style is on interpersonal behavior and interactions This leadership style has been shown to be beneficial for effective overseeing of teams [30]. Participative leadership allows for sharing of knowledge, and professional development of team members [31]. Studies have shown that participative leadership increases team members' commitment, and allows for acceptance of change and effectiveness [32]. This style is associated with improved team motivation and attitudes toward the tasks at hand [33].

Leadership has a profound effect on managing the response to routine public health events, as well as those that are catastrophic. Weak leadership can magnify the effects of public health emergencies. Strong leadership will significantly reduce the effect of emergencies [34]. What is often the case, strong and effective leadership is not seen because its success reduces the awareness of its effect [35].
