“A variable that is not in itself directly relevant, but that serves in place of an unobservable or immeasurable variable. In order for a variable to be a good proxy, it must have a close correlation, not necessarily linear, with the variable of interest.” (related: revealed preference; Proxy War — “A conflict between two nations where neither country directly engages the other.”)
Source:
Gabriel Weinberg’s Mental Models I Find Repeatedly Useful
