Q.A college student can either attend a 3-hour evening class or work a part-time job during those same 3 hours, earning ₹200 per hour. If she chooses to attend the class instead of working, what is the opportunity cost of attending the class, in rupees? If, instead, the job paid ₹250 per hour, how would the opportunity cost of attending the class change?

Opportunity cost is the value of the next-best alternative forgone when a choice is made. Because resources are scarce, using them one way means sacrificing what they could have produced elsewhere — and that sacrifice is the true economic cost of the decision.

Why it matters

Since resources have alternative uses, the real cost of any activity is not just the cash spent but the benefit of the option abandoned. This is why economists distinguish:

• Explicit (accounting) costs — actual cash payments recorded in the ledger
• Implicit costs — opportunity costs of owner-supplied resources, not in the books

Link to the Production Possibility Curve

Opportunity cost underlies the PPC: producing more of one good forces society to give up some of another. The slope of the PPC (the marginal rate of transformation) is opportunity cost, and its increasing slope reflects rising opportunity cost.

Quick example

A person runs their own shop instead of taking a job paying ₹6,00,000 a year. The shop earns an accounting profit of ₹5,00,000:

1. Explicit costs (rent, goods, wages) are already deducted → accounting profit ₹5,00,000. …