So to answer this question, we must first define what the PPF represents. Production Possibility Frontier shows the maximum possible output combinations of two goods and or services an economy can obtain when all resources are efficiently and fully employed. Thus knowledge in your theoretical PPF is the maximum possible combination when you use resources, such as high school and college. The other alternative would be a trade school or minimum wage etc. Also, consider the law of diminishing returns and how it applies. We move up and down the PPF curve and choose education to reach efficiency on the curve.
