Which of the following is Not a factor that causes empires to fall or decline? A. Healthy economy

B. Political corruption

C. Military defeat

B.political corruption

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.