A local restaurant in Hyde Park, a neighborhood of Chicago, Illinois, has a restaurant called Mellow Yellow. In the 1980s when I lived in Hyde Park, they offered some of the best and simplest meals, such as a Peasant Style Lunch. A glass of wine, a small loaf of bread, French onion soup, apple, and cheese. (The restaurant is still open, but the menu looks quite different.)

Lunch specials were offered to consumers willing and able to pay the going market price. The restaurant operated with a fixed capital input. They could not increase the size of their kitchen or serving area. There were only 10 employees in the establishment. As demand for their lunch specials increased, the owner considered increasing the number of employees.

Is this the short run or the long run? How do you know?