Final answer:
Constant returns to scale is the degree of returns to scale in the production function where the average cost of production does not change as output increases.
Step-by-step explanation:
Constant returns to scale is the degree of returns to scale in the production function. It refers to a situation where the average cost of production does not change as output increases. This means that if all inputs are increased by a certain percentage, output will increase by the same percentage without any change in average cost.