If the quality of conversations declines with size, here is one reason that groups might get too large (from the perspective of a benevolent social planner):
Conversations vary in their desirability—whether because of random drift in topics, the presence of fun people, access to the comfortable seating, or whatever. So by default some conversations will be better than others. This is partially visible from outside, whether by observing how much people are laughing, looking for the cool kids, or just gravitating to the couch.
If any conversation looks better than other conversations, then selfish conversational participants will preferentially join that conversation. We’d expect this to continue until the marginal party-goer is indifferent between each of the conversations. This will cause the good conversations to become larger and larger until they are no better than any other conversation.
To see how this leads to a problem, suppose that you have a house with a large number of spaces for conversation, one of which is nicer than the others—and simplify everything maximally, assuming that all conversation participants are interchangeable and that adding more people really just makes discussions worse (ignore the fact that you would obviously never throw a party in this world).
Then you end up with a bunch of 2 person groups, and one N person group using the nice space, where N is just large enough that the N person conversation is no better or worse than one of the 2 person groups. The net effect is exactly the same total welfare as if you had no nice space at all.
Of course the same thing happens if you add one person who is the life of the party, improving the quality of whatever conversation they are in. If you add just one such person, then the group containing them will grow until it is large enough to totally offset their value add.
The effect is less stark once you add enough cool kids and nice spaces—eventually a rising tide lifts all boats—but in general this kind of dynamic could lead to a leveling down to whatever the quality of the “reservation conversation” is, obliterating any gains from nice spaces, particularly fun people, or conversations that happened to go in a really interesting and fulfilling direction. (I’m not really sure about this last one, since if conversations sometimes go in an interesting direction then that also increases the expected value of starting a new conversation.)
To the extent that this is an important dynamic, there are possible fixes. A very brutish solution is just having a strong norm against joining conversations once they reach a certain size. If you could exogenously determine social judgments, you could deem it impolite to join 4-5 person conversations, taboo to join 6 person conversations, and good etiquette to leave 4-6 person conversations unless you are feeling particularly engaged.
If the quality of conversations declines with size, here is one reason that groups might get too large (from the perspective of a benevolent social planner):
Conversations vary in their desirability—whether because of random drift in topics, the presence of fun people, access to the comfortable seating, or whatever. So by default some conversations will be better than others. This is partially visible from outside, whether by observing how much people are laughing, looking for the cool kids, or just gravitating to the couch.
If any conversation looks better than other conversations, then selfish conversational participants will preferentially join that conversation. We’d expect this to continue until the marginal party-goer is indifferent between each of the conversations. This will cause the good conversations to become larger and larger until they are no better than any other conversation.
To see how this leads to a problem, suppose that you have a house with a large number of spaces for conversation, one of which is nicer than the others—and simplify everything maximally, assuming that all conversation participants are interchangeable and that adding more people really just makes discussions worse (ignore the fact that you would obviously never throw a party in this world).
Then you end up with a bunch of 2 person groups, and one N person group using the nice space, where N is just large enough that the N person conversation is no better or worse than one of the 2 person groups. The net effect is exactly the same total welfare as if you had no nice space at all.
Of course the same thing happens if you add one person who is the life of the party, improving the quality of whatever conversation they are in. If you add just one such person, then the group containing them will grow until it is large enough to totally offset their value add.
The effect is less stark once you add enough cool kids and nice spaces—eventually a rising tide lifts all boats—but in general this kind of dynamic could lead to a leveling down to whatever the quality of the “reservation conversation” is, obliterating any gains from nice spaces, particularly fun people, or conversations that happened to go in a really interesting and fulfilling direction. (I’m not really sure about this last one, since if conversations sometimes go in an interesting direction then that also increases the expected value of starting a new conversation.)
To the extent that this is an important dynamic, there are possible fixes. A very brutish solution is just having a strong norm against joining conversations once they reach a certain size. If you could exogenously determine social judgments, you could deem it impolite to join 4-5 person conversations, taboo to join 6 person conversations, and good etiquette to leave 4-6 person conversations unless you are feeling particularly engaged.