Why this is mistaken
The frontier is read as destiny: points on it will occur, points beyond it can never occur, and points inside prove capacity was destroyed. That gives the diagram claims its assumptions do not support.
Repair the model by attaching a dated assumption box: resource set, technology, quality, two outputs, and period. A boundary point is attainable and productively efficient under those conditions, not necessarily selected. An outside point is unattainable now. Actual production can move inside the same frontier, while new capacity or technology can shift the frontier itself.
Diagnosis requires you to label a point and then separately state what would have to change for the label to change.
Where to watch
When this mistake may appear
- A point lies outside the current frontier.
- A model draws one smooth boundary with two outputs.
- Technology or resources change between periods.
Check your work
Your work may contain this mistake if:
- Says a frontier point must be produced because it is efficient.
- Calls an outside point impossible under every future condition.
- Attributes an inward actual-production movement to lost capacity without evidence.