Several decades ago, the London Times editorialized about the Concorde, a supersonic plane. The Times stated that British taxpayers had spent 300 million (over $2 billion in terms of money today) to help develop the plane. Because this vast sum of money had been spent, the Times concluded that any decision to cancel the plane was nonsensical and, consequently, the only reasonable decision was to finish the project. Does this reasoning make economic sense? Why or why not? (Incidentally, the plane was finished and flew for 27 years before it was retired in 2003.)