250-350 words with 2 citations

De Pree (2004) writes, "Leaders, in a special way, are liable for what happens in the future, rather than what is happening day to day. This liability is difficult to measure, and thus the performance of leaders is difficult to measure" (p. 114). How does this differ from Covey's message in The 7 Habits of Highly Effective People? How can you measure your own success as a leader, or the leadership of those under your supervision?