Consider a community where many people remain a relatively short time. For example, a university department with 100 post-docs. Some stay for one year, some for three, some five. The community is growing, and 1 in 4 has started in the last 9 months. Older members (by membership age, not biological age) are now a minority who note that back when I was new, we all knew each other, but now we don't. The absolute turnout to departmental events such as shared coffee breaks and pub evenings is shrinking as the community gets larger.

How can social coherence be promoted in a group with a high renewal rate?

Although the example is of a university department, I think answers need not be specific thereto.

Consider a community where many people remain a relatively short time. For example, a university department with 100 post-docs. Some stay for one year, some for three, some five. The community is growing, and 1 in 4 has started in the last 9 months. Older members (by membership age, not biological age) are now a minority who note that back when I was new, we all knew each other, but now we don't. The absolute turnout to departmental events such as shared coffee breaks and pub evenings is shrinking as the community gets larger (people are reluctant to attend social events, as nobody they know are going).

How can social coherence be promoted in a group with a high renewal rate?

Although the example is of a university department, I think answers need not be specific thereto.