How about an example to illustrate decreasing marginal returns? Suppose that Flex-Star Plaque Company. produces the wildly popular Flex-Star Interactive Trophy Plaque (the wall plaque that broadcasts accomplishments to any who pass by). The Flex-Star factory, located on the outskirts of Shady Valley, is filled with the machinery, tools, and equipment--the fixed capital inputs--needed to produce Interactive Trophy Plaques.

• The Flex-Star factory currently employs six workers (Dan, Deanna, Doug, Debra, Donnie, and Duncan) who are busily engaged in Trophy Plaque production. By dividing the tasks and effectively using the Flex-Star factory and related equipment, these six workers encounter increasing marginal returns. Dan cuts the wood. Deanna does the sanding. Doug programs the voice modulator. Debra polishes the metallic-looking plastic figurine. Donnie does the packing. And Duncan is in charge of shipping.


• The factory currently turns out 100 plaques an hour, but demand is growing and Flex-Star needs even more production. Because the Flex-Star factory and associated capital is fixed in the short run, the only option is to hire more workers. So onto the payroll comes Barbara, Brian, Bruce, and Becky. The curious thing about this second batch of B-workers is that they are increasingly LESS productive than the original D-workers. Is this because they are less skilled? Absolutely not. The Ds have the same skills, training, and experience as the Bs.


• No, the answer to this productivity mystery rests with the fixed capital. The original D-workers perform the critical tasks (programming, polishing, packing, etc.) needed to produce Interactive Trophy Plaques. The B-workers can boost total plaque production by assisting the Ds, fetching materials and equipment used by the Ds, and taking over when the Ds are on lunch and coffee breaks.

  But because the size of the Flex-Star factory and the amount of capital it contains are fixed, there is only so much that the Bs can do. Barbara cannot use the table saw at the same time Dan is using the table saw. There is only one table saw. While total plaque production increases with the addition of each B-worker, the incremental boost in production declines with each additional B-worker.