回答： 诺基亚。领导者在苹果手机刚出来时，进行了一番两种手机的对比，认为苹果没有竞争力，因而没有开始与苹果竞争。决策失误，对消费市场的判断失误。中国牛奶，被发现有害物质，领导者主动指示还是疏于检测？ Most of the times, the leader of an enterprise is the main engine of a enterprise. However, there are many other reason might lead to the deterioration. For example, the shock in demand, a very strong competitor, or simply policy changes. We cannot argue that all the reasons that an enterprise goes downhill have something to do with its leader.

回答： 没有创新，市场定位不准确，技术水平下降。However, the more commonly seen case is a company goes downhill during the fierce competition with its market competitors. Sometimes a new leader is really helpful for an enterprises's revitalisation. After a long period of being in the leading position, it's highly possible that the leader of the enterprise would start being more satisfied about the current situation and starting being afraid of losing the existing achievements that they achieved in early days. If that is the case, changing a new leader would break this situation and bring the enterprise into a more aggressive situation again by new policies, new strategies and less fear of losing previous achievements.

回答： 带来新的方法和思想，也能更加客观地看出上一任的优缺点。 弊端：政策不连贯，总是换方向，越搞越乱。 Of course changing leaders might have some good effects on enterprise. However, the benefit of new leaders are varied among different industries and fields. Some big enterprise would grown a "relationship net" among the executive members of the enterprises. It is very possible that some "rent-seekers" would take advantage of the static situation and plot to get some benefit for themselves. A new incoming leader would bring changes to the inner relationship framework and break "rent seeker"' secret hope, and "clean out" the corrupted behaviour to some extent.

回答： If the reason that the enterprise starts deteriorating is that its leaders make mistake on very critical things such as market strategies, how much and what product to produce, or executive decisions on leadership positions, as long as there are more capable person that can take over the leadership position, the enterprise should change its leader. However, if the two conditions cannot be fulfilled, I personally don't think it's wise to change the leader of this company,

回答： Improve the institutional structure in an enterprise, improve efficiency pf decision making and reduce the possibility of approving a wrong decision. Having more good employees. Seek for the incentives of innovation. Create good enterprise culture.