The long run
The time period when all factors are variable, although technology is assumed const ant. If capital were the fixed factors the firm may now receive and operate new capital. Note that once such capital is installed the firm moves into a new short-run situation, and can only vary output by using more or less of variable factors with the new volume of fixed factors. As such, the long run can be thought of as a series of short-run situations. It may also be thought of as a planning period as it is in the long run that the firm can plan to set up a new scale of plant.