Positive Sum Design: The Importance of Rival, Non-Rival, and Anti-Rival Goods

In my last medium article on Positive Sum Design, I claimed that design is, by its very nature, a positive sum endeavor. This article intends to expand on that idea by exploring the difference between rival goods, non-rival goods, and anti-rival goods. Understanding these ideas and their implications is key to designing for positive sum-ness, and therefore to better design.

Let’s begin by defining each of these terms:

A rival good is any good for which consumption by one entity reduces possible consumption for another. Examples of rival goods might be the water in a water bottle on a hot day, the cake at a big birthday party, or hierarchical status in a social group. For each of these “goods,” consumption by one individual means that others cannot consume as much, or may not be able to consume at all. This is a little subtler, but very important, in the example of the social hierarchy: if one person moves up the hierarchy, another person must move down. There exist varying degrees of rival-ness in goods as well — for a good with extremely high rival-ness, even a small amount of consumption by one individual may lead to large losses in the ability for others to consume. One example of this might be someone with the stomach flu eating a family-style mean with others, but not taking precautions to mitigate the spread of their illness and therefore noticeably contaminating whatever food they consume. They may only eat a small amount of a certain dish, but since the dish is contaminated, no one else may eat it lest they wish to risk getting sick themselves. Rival goods are the backbone, the philosophical underpinning, of zero sum games. The erroneous human assumption that most goods are rival goods is the basis of the zero sum bias.

A non-rival good is a good for which consumption by one entity does not preclude or affect consumption by another. A classic example of a non-rival good is knowledge, or ideas: one person learning and understanding an idea does not impede another person from learning that idea as well. Non-rival goods are one important pillar of positive sum-ness, and identifying them is essential to the practice of Positive Sum Design.

An anti-rival good is the opposite of a rival good (as its name suggests). Anti-rival goods are characterized by consumption by one entity increasing the amount for others to consume. This might seem impossible at first blush, but I assure you it is not. You have likely used many anti-rival goods. For example, Wikipedia is an anti-rival good: the more people who use and interact with Wikipedia, the more entries it has and the more reliable it becomes (leaving the issue of internet trolls aside). Anti-rival goods are like superfoods for positive-sum systems in that they are incredibly positive-sum. However, with great power comes great responsibility — anti-rival goods can lead individuals in the anti-rival system to pressure or coerce others to join in, because that interaction creates valuable, consumable goods for the individuals already in the system.

Goods many also have complicated “rivality functions,” i.e. depending on various factors, a good may be an anti-rival good in one context, but a rival good in another. Take the example of a book club: when the club is small, it is an anti-rival good: extra members joining in the club might add to the number of voices and perspectives about the book, deepening conversations and adding value. At some point, however, each additional person begins to make the club less personal, less intimate. Things begin to feel cramped, and there isn’t enough time for everyone to speak freely about their experience of the book. At this point, the club has entered a rival good regime. But say people keep joining the club: the book club will eventually get so large that each additional person doesn’t really change the dynamics — everything has already become impersonal, and the club may have even found new ways of structuring itself to become scalable and deal with the high number of people. The club has ultimately entered a non-rival regime.

So, why does this matter to design?

If we accept my supposition that design should explicitly seek to create positive sum situations, then understanding and identifying goods’ rivality (or their “rivality function”) becomes an invaluable step in the design process. Only when the designer understands the dynamics or rivality in the context in which they design can they deliberately design positive sum systems. For instance, this may involve designing affordances and constraints into a system to ensure that its rivality function(s) never enter a rival-good regime. Or it may involve re-framing to introduce non-rival goods, or bring-to-the-fore already existing non-rival goods, into the system (see Ian Gonsher’s piece on The Mutability of Constraints).Whatever the strategy, Positive Sum Design requires designing with rival, non-rival, and anti-rival goods.

Article thumbnail courtesy of Will Francis via Unsplash