The Sunk Cost fallacy is a type of Relevance fallacy:
"It is often important for businesses to distinguish between relevant and irrelevant costs when analyzing alternatives because erroneously considering irrelevant costs can lead to unsound business decisions."
-- Garrison, Noreen, Brewer (2007)
Managerial Accounting 12th Ed. (p. 578)
Sunk costs are irrelevant costs. https://en.wikipedia.org/wiki/Relevant_cost
The quote brings to mind the idea that using inconsistent or unknown information in logical inference* is invalid. For example, although the statement
\[ p \wedge q \Rightarrow q \]
is true in binary logic, it is actually invalid in more general relevance logics (e.g., RM3) when \( q \) is inconsistent or unknown.
One might call this notion pseudo-relevance; inconsistent (or unknown) is not exactly the same thing as irrelevant; I'd love to see somebody expand on that.
* Strictly speaking, reasoning towards or from an inconsistency is invalid
#RelevanceFallacy #RM3 #SunkCosts