Opportunity cost is usually defined as the value of the next best opportunity. In the context of national production, the nation has opportunities to produce lemonade and yoghurt. If the nation wants to produce more yoghurt, because of labour resources are scarce and fully employed, in order to increase yoghurt production, it is necessary to remove the worker from the production of lemonade. The loss of lemonade production, which is necessary to produce more yoghurt, represents the opportunity cost for the economy