Tragedy of the Commons as an Economic Parallel to Cancer
Kept 'meh' post as reminder to self. Take your time. Get a proper understanding of peoples' views before submitting own two cents. (ooft).
This post is a quick response to Michael Levin’s quest to find a suitable parallel for cancer in economics.
Context: Levin’s request
In the video below, Michael Levin requests economic parallels to biological malfunctions/disorders in living systems. Examples include (from 50 minutes):
Developmental defects
Failure to repair
Cancer.
What is cancer?
My understanding of Levin’s take is that:
Cancer involves the cell having a narrower definition of ‘self’ than optimal
This causes the cell to prioritise itself (and its growth) at the expense of broader system functioning, which can lead to the death of the entire organism (and thus, the cancer itself).
A Parallel: the Tragedy of the Commons
Characterising the Commons
In economics, there is a category of resources called ‘common pool resources’. In essence, these resources are characterised by the following:
They are rivalrous (one person’s use reduces availability for others)
They are non-excludable (it is difficult to prevent anyone from using it).
This relates to the concept of Common land, i.e., land in which all persons have common rights, such as to allow their livestock to graze upon it, to collect wood, or to cut turf for fuel. The classic example is of pastures:
Pastures are rivalrous - When one cow grazes on a pasture, it eats the grass (the grass is no longer available to feed other cows)
Pastures are non-excludable - On common land, everyone can allow their livestock to graze.
A challenge is that common pool resources may be destroyed by overuse. In our example, overgrazing means all the grass is eaten, leaving none available for anyone else, and potentially killing off the resource entirely (the ground becomes barren).
An Agent’s Decision
Let’s think of an agent’s decision to graze their cows. It’s essentially:
Individual gain: My cow gets fed
Collective cost: The common resource depletes (for others and me).
What then affects the agent’s decision to graze their cows?
How much I think I gain from feeding my cows
How much I think I lose from depleting the resource.
The perceived loss from depleting the resource may vary. Here are some factors that influence the agent’s decision:
The belief that others will overgraze and destroy the land:
If I believe that others will overgraze, then I may as well beat them to the punch. I like to call this the ‘Race to the Bottom’, but really, it’s just a finite game + rollback (see: Robert Axlerod’s The Evolution of Cooperation).
Low dependence on the resource:
If I’m highly mobile, I can just overgraze and move elsewhere. The flip of this is someone who is highly dependent on or attached to their land, i.e., if they overgraze, their cattle will no longer eat, and they will starve.
Further beliefs regarding future resource availability
The belief that resources will die regardless of what you do
The belief that the resource will be able to regenerate itself.
Lack of concern for others’ access:
If I care less about their access to resources, I’m more likely to deplete it
Other players could make me care (i.e., via deterrence strategies)
For example, by stealing my cattle
That is, they could impose costs or reduce my gains
Strong preference for today rather than tomorrow:
If I have a preference for today over the future, I’m more likely to deplete the resource to the detriment of my future self (see: exponential/hyperbolic discounting in behavioural economics)
This can be viewed as an economic necessity, e.g., “Gotta to steal to eat!”
Tragedy of the Commons
For the sake of our exercise, we begin with a common pool resource that exists, meaning it was either free from human intervention or humans were using it in a sustainable manner.
Now, for whatever reason (including those listed above), the agent could choose to continue grazing their cows until the common resource is depleted. This is termed the Tragedy of the Commons by ecologist Garrett Hardin (1968), whereby:
…Each man is locked into a system that compels him to increase his herd without limit – in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons.
That is, the individual overconsumes and so doing destroys the common resource.
Sample Solutions to Tragedy of the Commons
These institutions mitigate resource degradation.
Property Rights
By defining ownership, we can promote care for resources (e.g., because the owner-agent may want to sell the resource or continue using it in the future). This process is called privatisation.
Of course, privatisation amounts to making the non-excludable excludable, and so, the Commons is no longer a Commons!
Governance structures
Elinor Ostrom’s 1990 book titled ‘Governing the Commons’ (available online) describes eight “design principles” of stable local common pool resource management:
Clearly defining the group boundaries (and effective exclusion of external un-entitled parties) and the contents of the common pool resource
The appropriation and provision of common resources that are adapted to local conditions
Collective-choice arrangements that allow most resource appropriators to participate in the decision-making process
Effective monitoring by monitors who are part of or accountable to the appropriators
A scale of graduated sanctions for resource appropriators who violate community rules
Mechanisms of conflict resolution that are cheap and of easy access
Self-determination of the community recognized by higher-level authorities
In the case of larger common-pool resources, organisation in the form of multiple layers of nested enterprises, with small local CPRs at the base level.
Prosocial’s David Wilson Sloan worked with Ostrom to generalise her principles.
Agencies and regulators
We might consider introducing a body that works to protect the common resource. These bodies can introduce regulations that prohibit types of action (i.e., impose constraints), or create incentives that promote ‘desirable’ behaviour.
But things can go awry, e.g:
Regulatory interventions can have unintended consequences, including by crowding out developmental processes
The regulator can too narrowly follow its objectives, to the detriment of the wider economy
Regulators can become corrupt, e.g., regulatory capture and the 'revolving door’.
Cultural factors
Most of the time, a common pool resource is overused because cultural norms have already been broken. Is it possible to create cultural/soft blockers to these dynamics?
Summary of parallel
And so, we arrive at a parallel:
Suppose
Cells = farmers and their cows
Cancer = farmers and their cows who over farm
Energy = grass
‘Human body’ = broader system (grass + field + farmers + cows).
The cancer consumes energy and expands to consume more energy
Scarcity of energy and space means growth is at the expense of other cells
Other cells cannot exclude it from these resources
The cancer jeopardises the functioning of the organism
The organism dies
Energy is no longer supplied to the cancer
The cancer dies.
Tragedy of the Commons and negative externalities (edited)
Lyons uses negative externalities as his parallel to cancer.
One definition of externality is a cost or benefit that affects a third party who did not choose to incur that cost or benefit. So a negative externality is a cost imposed on a third party who did not choose to incur it.
Then, is cancer an example of a negative externality? Yes, absolutely.
But can we be more speciffic? My first throught was that the Tragedy of the Commons is suitable given it appears to capture the dynamics of cancer. The story starts with a happy state of cooperation. Then, for whatever reason, the cancer begins to overuse the shared resource. Then, because other cells cannot exclude it from resource access, it overconsumes to the detriment of the whole. The story ends with a dead organism and a dead cancer. That is, the cancer kills itself by its continued growth, the king of ‘own goals’.
Now, is this a good parallel? The answer rests on the applicability of the assumptions…
End note
Another great video from Levin, with thought-provoking insights from Lyons.
So that further parallels can be drawn to economics, it would be good to get:
A list of the different malfunctions/disorders in living systems, e.g., developmental defects and failure to repair
Their definitions.
Finally, it should be noted that economics itself is very general. It is all about resource allocation. And there are many different allocative mechanisms, e.g.:
Money prices and free market capitalism: private property and exchange of goods and services using money price (e.g., one apple for $1)
Bartering: exchange of products using relative prices (e.g., one apple for two bananas)
Planned economies and technocracies: where ‘experts’ determine how resources should be allocated
Wait times and queuing: implicit cost of waiting in line (e.g., you get one apple if you stand in line for 1 hour)
Coercion: implicit cost of developing the ability to coerce (e.g., you get one apple if you beat up the store owner and take it).
I say this to avoid falsely constraining the search space for possible economic systems. This is something highlighted by David Graeber in his book, The Dawn of Everything.
I would love to hear your thoughts on the above.
Brydon
About me (disclaimer, in case sensitive to credentials):
I’m no biologist
I’m no elite PhD economist.
Thanks for sharing your thoughts, Brydon. The tragedy of the commons is a subset of externality, so I don't think there's any substantive disagreement between us.
Categorization decisions, like all decisions, are about utility. The tragedy of the commons occurs when people have trouble excluding others from using some resource. This could be due to a lack of legal rights to exclude (e.g., no one owns the commons) or due to a technological inability to exclude (e.g., your fence isn't tall enough to keep people out). But externality in a broader sense is simply about the lack of connections between people. Based on my limited understanding of the tissue organization field theory, cancer seems to be due to a lack of connections between cells rather than the inability to exclude. Undoubtedly you could try to frame it both ways, so at that point it's a question of which framing works better in practice for generating interesting and useful ideas.