Nonexcludability — no individual or group can be excluded from enjoying the benefits a resource may confer, whether they contribute to its provision or not.
非排除力——没有个体或团体可以被排除在资源可能授予的效益中，不管他们为它做出供应与否。
2
A public good has two attributes: nonexcludability, which means the producer can't prevent the use of the good by others, and nonrivalry, which means that many people can use the good simultaneously.