What is opportunity cost?

Opportunity cost is the value of the best alternative forgone when a choice is made. Money, time, labour and land are limited, so using a resource for one purpose reduces other possibilities. The concept considers benefits that cannot be obtained as well as bills actually paid.

How is opportunity cost identified?

1. Identify realistic alternatives First establish the available uses of a resource. An evening might be spent working, studying or resting, but all choices may not be possible together. Opportunity cost is the value of the best feasible alternative, not the sum of every rejected option. 2. Explicit and implicit costs A course fee is an explicit cost; income from paid work that cannot be performed during the course may be an implicit cost. Even a free course uses time. However, if no work was actually available during those hours, treating a hypothetical wage as lost income would be misleading. 3. A business example A business using its own building may pay no rent. The net rental income it could obtain by letting the building is nevertheless an opportunity cost. Maintenance, potential vacancies and other expenses should be included in a realistic comparison.

What matters when making a decision?

4. The difference from sunk costs A past expense that cannot be recovered is a sunk cost. Money already spent on a project does not by itself justify further harmful spending. A continuation decision should consider future benefits, expenses and alternatives. 5. Marginal analysis Decisions are often not all-or-nothing. The benefits and costs of another hour of work or another unit of production can be compared. Average cost can differ from the additional cost of the last unit. 6. Values beyond money Health, family time and environmental effects also matter. Allocating a public budget to one purpose affects resources left for other services. Opportunity-cost analysis does not dictate one correct choice; it makes the forgone benefit visible.