Final answer:
The attribute not identified as an effective board member trait in the textbook is 'c) Unknown in their field'. Effective board members are generally known for mentoring capabilities, experience, strong networks, and pattern recognition.
Step-by-step explanation:
The attribute of an effective board member that was NOT identified in the textbook is c) Unknown in their field. Effective board members possess several key attributes that enable them to contribute positively to the governance and strategic direction of a firm. These attributes include a) Ability and willingness to mentor the CEO and top managers, b) Investment and/or operating experience, d) Strong personal and professional networks, and e) Pattern recognition skills.
The efficacy of a board member is crucial because they help ensure that the firm operates in the interests of its true owners, the shareholders. The textbook highlights how the top executives choose board members and discusses the importance of the directors' roles in light of imperfect information in the market. Board members who are unknown in their field do not typically provide the necessary insight, trust, and networks deemed essential for guiding the firm and mentoring its executives.