Why a good mission statement leads to better productivity?

Waiting for the information , in my opinion, is one of the most important productivity killer. The information lag is compounded when a person whose work is dependent upon the information from multiple sources, is stuck. The problem is that even though something may be important for one , it may not be in the priority list of one's co-workers . Then a lot of time gets wasted in following up and getting the required information . But is co-worker to be blamed for lack of enthusiasm. Probably not. Any organization needs to work for a certain objective, irrespective of the size. The mission statement defines how people working for the organization behave. If the mission statement does not provide adequate direction to the employees,  they probably will not know their priorities. But just having  a great mission statement will not create productive workforce. The objectives derived out of the mission statement needs to be clarified time and again by the senior management. The objectives derived out of mission statement need to have a direct impact on the way of working of the employees. McDonald’s objective is for example .(from Wikipedia)
To provide the fast food customer food prepared in the same high-quality manner world-wide that is tasty, reasonably-priced & delivered consistently in a low-key decor and friendly atmosphere.
This is a mission statement that sets concrete ideas for a food chain to deliver cost effective food which is tasty. The information problem that I highlighted is often because of two factors a) There is no concrete and clear mission statement b) Senior management is lethargic/does not find enough time to implement the objectives If the organizations go by their mission statement, productivity would be far higher. For example, if the objective is to provide customer a response in four hours, everyone will do his/her bit to do that. The targets would be set and the service levels could be measured easily. Then in the case of the example at the top of this post, everyone will provide information needed to fulfill the objective. I used to be of the opinion that mission statements are only a cursory feature meant to impress stakeholders. However an excellent and concrete mission statement which leads to meaningful objectives is a far bigger gain on productivity than any other costly tool or system. No matter if you lead a team of ten or a hundred, a good mission statement is a must.