Final answer:
The return to education is lower when there is a higher supply of individuals with that level of education.
Step-by-step explanation:
The return to education is lower when there is a larger supply of educated individuals. When there is a higher demand for a particular level of education, such as a PhD or specialized medical degree, there tends to be a lower supply of individuals with that level of education. This lower supply leads to higher returns for those who have attained that level of education.
For example, there is a lower supply of PhD mathematicians compared to high school mathematics teachers, resulting in higher returns for the mathematicians. Similarly, there is a lower supply of cardiologists compared to primary care physicians, leading to higher returns for the cardiologists.
So, in summary, everything else being identical, the return to education is lower when there is a higher supply of individuals with that level of education.