Granovetter 1973 (AJS) — strength of weak ties; surveyed Newton MA men found jobs more through acquaintances than close friends

Claim: Granovetter (1973) established that the degree of overlap between two individuals' networks varies directly with the strength of their tie. Strong ties cluster — your closest contacts tend to know each other. Weak ties bridge — your acquaintances are more likely to introduce you to information and people outside your immediate cluster.

Empirical anchor: a survey of how 282 men in Newton, Massachusetts got their jobs. Surveyed men more often found employment through acquaintances than through close friends.

Source: Granovetter, M. S. (1973). "The Strength of Weak Ties." American Journal of Sociology 78(6), 1360–1380. https://www.cs.cmu.edu/~jure/pub/papers/granovetter73ties.pdf

Confidence: Verified (one of the most-cited papers in sociology).

For Candid: Granovetter's original strong claim — weak ties as uniquely valuable — was walked back in [[granovetter-1983-weak-ties-revisited-walked-back]]. The applied lesson for trades is that the contact at the supply counter or the HBA event whom you barely know is more likely to introduce you to a new client than your closest professional ally — for information about novel opportunities. The closest ally is more likely to deliver the high-trust referral once an opportunity is identified.