The Basics
- Simple definition: The short run is a period where at least one factor of production is fixed; the long run is a period where all factors can be varied.
- Core idea: Time horizon determines what adjustments are possible.
- Think of it as: Short run, you’re stuck with your current factory; long run, you can build a new one.
What It Actually Means
The distinction isn’t calendar time – it’s about flexibility. In the short run, firms have fixed inputs (plant size, machinery) and can only adjust variable inputs (labor, materials). They may operate at a loss if covering variable costs. In the long run, all inputs are variable – firms can enter/exit industries, build new plants, and adopt new technology. Short-run decisions are about utilization; long-run decisions are about capacity and strategy.
Example
A Pakistani steel mill with fixed plant capacity: short run – can hire more workers, run extra shifts, but can’t expand the factory. Long run – can build new plant, install new technology, or exit industry entirely.
Why It Matters
The distinction explains cost behavior, supply elasticity, and industry dynamics. Short-run supply is less elastic; long-run supply is more elastic. Policy impacts differ over horizons.
See also
Fixed Costs • Variable Costs • Production Function • Returns to Scale • Entry and Exit
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