Concorde Fallacy / Sunk Cost Fallacy

Richard Thaler coined Sunk Cost Fallacy in 1980. The Concorde Fallacy was coined in 1956, source unknown.

At any moment in time, the best thing to do depends only on current alternatives. In other words, the only things that matter are the future consequences. Past mistakes are irrelevant, as they are "sunk".

"The sunk cost fallacy has also been called the "Concorde fallacy": the UK and French governments took their past expenses on the costly supersonic jet as a rationale for continuing the project, as opposed to "cutting their losses".

Source: Wikipedia

Also relevant: Plan continuation bias