Thank you for suggesting this thread. It was I who suggested this question as suitable for further exploration.

“Informal authority” is very far from what I would have suggested Sociology specialized in. Probably I would have said either “the description of modern western, industrial societies,” or “the study of modern societies more particularly in terms of categorizing individuals and groups into classes, strata, ranks, and occupational groups, and with a focus (at least partially) on modern bureaucracy and formal record keeping by organizations.

In that sense, Anthropology seems more interested in the “informal” than Sociology does, to the extent that they are both studying the same situation.

Sociology tends to study formal bureaucracy, with a preference for written records.

= – = – = – =

As I recall, the triumvirate of founders of Sociology are

Marx
Weber
Durkheim.

So I have seen it enumerated–but where? not sure.

= – = – = – = =

An aphorism pops into my head, unbidden:

“Economics studies how people make make choices, and
Sociology studies how people don’t have any choices to make. ”

Obviously if Economists study choice and Sociologists think people don’t have much choice, the practitioners of the two disciplines are going to have trouble seeing eye to eye or understanding each other.

http://conversableeconomist.blogspot.com/

Today 10/9/2017 (Monday)

That makes two in a row,

“Sociology is about what people say they value;
economics is about what people show they value.”

I did read too many sociology articles that relied on “surveys”: asking people questions in a fairly unsophisticated way and then drawing strong conclusions.