I'm feeling that there's a kind of ratio to associate with a manager's communications that I call the "silence to signal ratio (SSR)." E-mail and voicemail have provided direct ways to measure one's own SSR. How many e-mails and calls do you fail to return? Versus how many do you actually return?
There is a critical equilibrium to achieve in your personal SSR because if your SSR is equal to 0.0 (0% silence for 100% communications) then you're pushing the edge of humanity. On the other hand if your SSR is equal to 1.0 (100% silence for 100% communication) then either you're living on a deserted island or your co-workers and reports have moved you there and you're just sadly unaware that this has happened. Thus a high SSR should be avoided. Instead, a low SSR should be maintained to achieve a high degree of mental health and productivity within your social network.