In microeconomic theory, the opportunity cost of a choice is the value of the best alternative forgone where, given limited resources, a choice needs to be made between several mutually exclusive alternatives. Assuming the best choice is made, it is the "cost" incurred by not enjoying the benefit that would have been had by taking the second best available choice. The New Oxford American Dictionary defines it as "the loss of potential gain from other alternatives when one alternative is chosen." As a representation of the relationship between scarcity and choice, the objective of opportunity cost is to ensure efficient use of scarce resources. It incorporates all associated costs of a decision, both explicit and implicit. Thus, opportunity costs are not restricted to monetary or financial costs: the real cost of output forgone, lost time, pleasure, or any other benefit that provides utility should also be considered an opportunity cost. Types of opportunity costs Explicit costs Explicit costs are the direct costs of an action (business operating costs or expenses), executed through either a cash transaction or a physical transfer of resources. In other words, explicit opportunity costs are the out-of-pocket costs of a firm, that are easily identifiable. This means explicit costs will always have a dollar value and involve a transfer of money, e.g. paying employees. With this said, these particular costs can easily be identified under the expenses of a firm's income statement and balance sheet to represent all the cash outflows of a firm. Examples are as follows: Land and infrastructure costs Operation and maintenance costs—wages, rent, overhead, materials Scenarios are as follows: If a person leaves work for an hour and spends $200 on office supplies, then the explicit costs for the individual equates to the total expenses for the office supplies of $200. If a printer of a company malfunctions, then the explicit costs for the company equates to the total amount to be paid to the repair technician. Implicit costs Implicit costs (also referred to as implied, imputed or notional costs) are the opportunity costs of utilising resources owned by the firm that could be used for other purposes. These costs are often hidden to the naked eye and aren’t made known. Unlike explicit costs, implicit opportunity costs correspond to intangibles. Hence, they cannot be clearly identified, defined or reported. This means that they are costs that have already occurred within a project,