In economics, a budget constraint represents all the combinations of goods and services that a consumer may purchase given current prices within his or her given income.
There are two major differences between a budget constraint and a production possibilities frontier. The first is the fact that the budget constraint is a straight line. This is because its slope is given by the relative prices of the two goods, which from the point of view of an individual consumer, are fixed, so the slope doesn’t change. In contrast, the PPF has a curved shape because of the law of the diminishing returns. Thus, the slope is different at various points on the PPF. The second major difference is the absence of specific numbers on the axes of the PPF. There are no specific numbers because we do not know the exact amount of resources this imaginary economy has, nor do we know how many resources it takes to produce healthcare and how many resources it takes to produce education. If this were a real world example, that data would be available.
- Principles of Economics 2e. OpenStax. Authors: Steven A. Greenlaw, David Shapiro. https://openstax.org/books/principles-economics-2e/pages/1-introduction