Public goods are goods and services that have two key characteristics: They are non-excludable and non-rivalrous. The first characteristic means that once the public good is provided, it is available for everyone to use (whether they pay for it or not). National defense, the classic example of a public good, protects everyone in the country. Once it’s provided, it’s provided for all. The second characteristic means that one person’s consumption or use of the public good doesn’t prevent other people from using it at the same time. An apple is a private good. If you eat the apple, no one else can. Public goods, like national defense, are usable by all simultaneously.

Now consider open educational resources. They have significant costs to develop, such as paying the author to write an open source book and editors to polish it, creating the online platform on which to host the book, etc. But once the OER is available, anyone can download a copy or use it, and one person’s consumption does not prevent other people from consuming it at the same time. Thus, OER are public goods! We know that public goods, because they are available for free, are under-produced by the market. Few individuals could afford to pay for national defense on their own, even if they were willing. Who pays the costs of creating OER? To date, most OER has been either created for free by the authors, or supported by private grants.