Answer:
an increase in the proportion of the population that is college educated
Explanation:
Economic growth refers to an increase in the gross domestic product of an economy owing to an increase in the level of output.
An increase in the national output of goods and services results out of increase in the productivity and capability of the workforce.
In the given case, when the graduate population of a nation increases, it would lead to an increase in the capacity owing to knowledge increase in the workforce.
Due to this, the nation shall move towards full employment level as jobs start getting filled up by the best suited person.
Productivity and production rises as a consequence and thus the national output rise increases the gross domestic product.