C​‌‍‍‍‌‍‍‌‌‍‌‍‍‌‌‌‍‍‍‍​ompare descriptive and prescriptive theories of leadership, and explain why both types of theory are use​‌‍‍‍‌‍‍‌‌‍‌‍‍‌‌‌‍‍‍‍​ful. Resources: Crisis Leadership, Planning for the Unthinkable, Ian I. Mitroff. ISBN 0-471-22918-​‌‍‍‍‌‍‍‌‌‍‌‍‍‌‌‌‍‍‍‍​0