Question: (a) Do diminishing marginal returns to a factor imply diminishing average returns to a factor?
(b) Do diminishing marginal returns to a factor imply diminishing returns to scale?
(c) If every factor generates diminishing marginal returns to a factor, does that imply factors are perfect substitutes for each other?
(d) If every factor generates diminishing marginal returns to a factor, does that imply that factors are perfect complements?