Diminishing returns on an exponential can still be exponential. Typically, diminishing returns means f(x) = x/(1+log(x)) where x is headcount and f is output.

Diminishing returns on an exponential can still be exponential. Typically, diminishing returns means f(x) = x/(1+log(x)) where x is headcount and f is output. The overhead goes up with the log of the number of people, because a hierarchical organization will have log(N) layers of management that need to be traversed to make decisions. If we have exponentially increasing manpower, x=exp(t), then f = exp(t)/(1+log(exp(t)) which is O(exp(t)/t)