During the course of a week, McDonald's has enough time to hire or layoff workers, but it does not have enough time to expand its kitchen or add an additional seating area. In this situation, McDonald's:

Mcdonald is operating in a short run

Explanation:

The short run is a concept where some factors of production are fixed and  others are variable.  it expresses the idea that a business will behave differently given the   length of time it has to react to certain circumstances.

In most cases of short run, Quantity of labor is variable but the quantity of capital and production processes are fixed making  the only available business decision is whether to employ or lay off workers number off. because it is easier to hire and lay off  workers than to cause a positive  change in areas of  production process or to change location.(:

McDonald's having enough time to hire or layoff workers, but  not having  enough time to expand its kitchen or add an additional seating area shows that Mcdonald is operating in a short run business where labor is variable but capital and other production processes are fixed.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

a photo collage of women at work during world war 2