Opportunity cost refers to what you have to give up to buy what you want in terms of other goods or services. When economists use the word "cost," we usually mean opportunity cost.
The word "cost" is commonly used in daily speech or in the news. For example, "cost" may refer to many possible ways of evaluating the costs of buying something or using a service. Friends or newscasters often say "It cost me $150 to buy the iPhone I wanted."
Definitions and Basics
Opportunity Cost, from the Concise Encyclopedia of Economics
When economists refer to the "opportunity cost" of a resource, they mean the value of the next-highest-valued alternative use of that resource. If, for example, you spend time and money going to a movie, you cannot spend that time at home reading a book, and you can't spend the money on something else. If your next-best alternative to seeing the movie is reading the book, then the opportunity cost of seeing the movie is the money spent plus the pleasure you forgo by not reading the book....
Getting the Most Out of Life: The Concept of Opportunity Cost, by Russ Roberts on Econlib
To get the most out of life, to think like an economist, you have to be know what you're giving up in order to get something else....
Sometimes people are very happy holding on to the naive view that something is free. We like the idea of a bargain. We don't want to hear about the hidden or non-obvious costs. Thinking about foregone opportunities, the choices we didn't make, can lead to regret. Choosing this college means you can't go to that one. Marrying this person means not marrying that one. Choosing this desert (usually) means missing out on that one....
Opportunity Cost, a LearnLiberty video.
Prof. Don Boudreaux explains what economists mean when they talk about unintended consequences.
Opportunities and Costs, by Dwight Lee. At CommonSenseEconomics.com. PDF file at CommonSenseEconomics.com first published in The Freeman
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