公共物品是相对私人产品而言,它既具有“共同消费”,又具有“非排它”性质的产品。所谓共同消费,指当某人消费着一定产品的同时,其他人亦可以消费同等量的产品;非排它性是指若对某一个人提供产品,相应地也要对他人提供相同量的产品。上面我们讲的公共物品是纯粹公共物品,但是在现实生活中,还有许多产品是非纯粹公共物品,如有些物品,其在消费时必须具备某种资格,并遵守某种规则,但是这种物品在消费时,某消费者之消费不会影响或减少其他会员对同一物品的消费,这种物品布坎南称之为“俱乐部产品”。 Public goods are relatively private goods, it has both “common consumption”, but also has a “non-exclusive” nature of the product. The so-called co-consumption means that when someone consumes a certain product, others can consume the same amount of product. Non-exclusive means that if a product is supplied to an individual, the same amount of product must be provided to others accordingly . The public goods we talk about above are purely public goods, but in real life there are many products that are not purely public goods, such as some goods that must have certain qualifications in consumption and comply with certain rules, but such goods When consumed, the consumption of a consumer does not affect or reduce other members’ consumption of the same item, which Buchanan calls “a club product.”