Why the health–bread frontier bends backward

Split Ed’s days and watch the curve appear

Drag the dot along the curve, or use the slider. Start at A and move slowly, keeping an eye on the red sick days.

Try this: find the spot where bread stops growing. How many sick days are left there, and why doesn’t Ed get rid of them?

Five points to know

Pick a point here or tap one on the graph.

Try this: pick E and look at the blue area. Then pick C. Why does the blue area disappear?

Where does Ed choose to be?

The frontier shows what Ed can have. His preferences decide where he wants to be: he picks the highest indifference curve that still touches the frontier.

Try this: slide all the way from left to right. Does Ed ever choose a point between A and C?

Check yourself

What shifts the whole curve?

Education and better medical care make each day spent on health more productive. Educated people tend to be more efficient producers of health, so their whole frontier sits further out.