Glossary term

Short Run

In economics, the short run is a period when at least one major input or constraint is fixed, so a business or economy cannot fully adjust to changing conditions.

Updated

May 16, 2026

Read time

2 min read

What Is the Short Run?

In economics, the short run is a period when at least one major input or constraint is fixed, so a business or economy cannot fully adjust to changing conditions. The exact length is not a set number of days or months. It depends on what is being analyzed.

For a business, the short run might mean a period when factory space, equipment, contracts, or staffing cannot be changed easily. For the economy, it may describe a period when prices, wages, capacity, or expectations adjust slowly.

Key Takeaways

  • The short run is defined by fixed constraints, not by a specific calendar length.
  • At least one input or condition cannot fully adjust in the short run.
  • Short-run decisions often focus on managing capacity, costs, prices, and demand with existing resources.
  • The long run is the period when more inputs and decisions can adjust.
  • The short-run concept helps explain why costs, output, inflation, and employment may respond unevenly to shocks.

How the Short Run Works

Suppose a company sees a sudden increase in demand. In the short run, it may be able to increase overtime, buy more materials, or run equipment harder. But it may not be able to build a new facility, redesign its supply chain, or hire and train a large workforce immediately.

That constraint changes the economics. Costs may rise, output may be capped, and prices may respond before capacity catches up.

Short Run Versus Long Run

Time frame

Main idea

Short run

Some inputs or conditions are fixed

Long run

More inputs, capacity, contracts, and decisions can adjust

Why the Short Run Matters

The short run matters because many financial and economic decisions happen before full adjustment is possible. A company may raise prices because capacity is tight. A central bank may respond to inflation before supply improves. A household may face higher costs before income catches up.

Short-run analysis is useful, but it can be dangerous when treated as permanent. A shortage, margin squeeze, or price spike may be real today without being the long-term state of the market.

The Bottom Line

The short run is a period when some important inputs or constraints are fixed. It helps explain why businesses and economies cannot always adjust instantly, even when demand, costs, or prices change quickly.

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