民防作为一个整体,是典型的纯公共物品。但是它实际上是一个由很多要素组成的复杂物品系统。一些具体要素是纯公共物品,如民防体制和民防法律政策、民防指挥工程设施、民防专业队防护工程等;而另一些具体要素,如人员掩蔽工程、物资库、医疗救护工程、疏散干道等,则在战时是纯公共物品,在平时是准公共物品。 Civil defense as a whole, is a typical pure public goods. But it is actually a complex item system made up of many elements. Some specific elements are purely public goods such as civil defense system and civil defense law and policy, civil defense directing engineering facilities and civil defense professional team protection engineering; while other specific elements such as personnel masking works, material depots, medical aid projects, Evacuation of roads, etc., in the wartime is a pure public goods, usually quasi-public goods.