Three managers of the van Heerven Coach Company are discussing a possible increase in production. Each suggests a way to make this decision.

FIRST MANAGER: We need to decide how many additional coaches to produce. Personally, I think we should examine whether our company’s productivity – number of coaches produced per worker per hour – would rise or fall if we increased output.

SECOND MANAGER: We should examine whether our average cost per worker – would rise or fall.

THIRD MANAGER: We should examine whether the extra revenue from selling the additional coaches would be greater or smaller than the extra costs.

Who do you think is right? Why?