(Answered) Do the following production functions have increasing, decreasing, or constant returns to school?…

➤ Why does the sum of exponents determine returns to scale in Cobb–Douglas functions?
The sum of exponents equals the degree of homogeneity. If the sum exceeds one, scaling inputs raises output more than proportionately (increasing returns); equal to one gives constant returns; less than one yields decreasing returns. This follows from scaling all inputs by the same factor and observing how output scales.