In economics, a margin is a set of constraints conceptualised as a border.
Margins are sometimes conceptualized as extensive or intensive.
extensive margin 是包含所有可用的：
An extensive margin corresponds to the number of usable inputs that are in some sense employed. For example, hiring an additional worker would increase an extensive margin.
intensive margin 只包含實際在用的：
An intensive margin corresponds to the amount of use extracted within a given extensive margin. For example, reducing required production from a given set of workers would decrease the intensive margin.
下面是關於“勞動力”這個概念的解釋：
In the context of the workforce, the intensive margin can refer to people already in the workforce. The extensive margin refers to all members of the labor force, employed and unemployed.
有些概念有廣義（extensive）和狹義（intensive）之分，或者說是外延和內涵。
你直接翻譯為 “廣義和狹義的範疇” 即可。
具體理解如下：
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margin就是對範圍的一個限定。這裡是對概念範圍的圈定。
In economics, a margin is a set of constraints conceptualised as a border.
Margins are sometimes conceptualized as extensive or intensive.
extensive margin 是包含所有可用的：
An extensive margin corresponds to the number of usable inputs that are in some sense employed. For example, hiring an additional worker would increase an extensive margin.
intensive margin 只包含實際在用的：
An intensive margin corresponds to the amount of use extracted within a given extensive margin. For example, reducing required production from a given set of workers would decrease the intensive margin.
下面是關於“勞動力”這個概念的解釋：
In the context of the workforce, the intensive margin can refer to people already in the workforce. The extensive margin refers to all members of the labor force, employed and unemployed.
intensive margin指所有在職工人的總數；而extensive margin指所有具有勞動能力的人的總數（含在職的和失業的）。