The economist's analysis in the scenario painted above incorporates the idea of OPPORTUNITY COST.
Opportunity cost refers to a value or a benefit which must be given up in order to enjoy or acquire another benefit. Because resources are scarce, one always has to make decision about how to use one's resources efficiently. In the scenario given above, Joe had the opportunity to put his money in a fixed deposit account or to use it to buy gold coins; he choose the latter given up the former. Thus, the former, which he gave up is his opportunity cost.<span />
