# any decision going forward should not be based on what has happened in the past > The “sunk costs” lesson. When the financial viability of an enterprise is questionable going forward, any decision to continue should not be based on what has already been spent. The Concorde partners learned this lesson 27 years, and lots of taxpayer money, too late. ([[Jim Blasingame#^bbv5u]]) We start thinking... - “I’ve got too much invested …” - “If I just work harder …” - “I just need more time ...” And maybe this is not just about money and business. But also about other things too. Obviously we want to learn lessons but we cannot base a 'perceived' future on our past. Like falling in love again after a bad relationship. > Economic theory suggests that [“…decisions should only be guided by future gains and losses, as prior costs do not affect the objective outcomes of current decisions.”](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0209900) ([[(Martin, 2019)#^7xfi7]]) > Reflecting when we’re [not mentally overwhelmed](https://www-ncbi-nlm-nih-gov.ezp.lib.unimelb.edu.au/pubmed/30620741) helps us to avoid the sunk cost fallacy. > Economic theory implies that decision makers’ decisions should only be guided by future gains and losses, as prior costs do not affect the objective outcomes of current decisions. Hence, the normative correct decision in sunk-cost situations is to ignore past investments. Taking into account past losses or investments is a decision strategy that has been dubbed the 'Sunk-Cost fallacy' or 'Sunk-Cost effect'. It is considered a mistake or faulty strategy. In more neutral terms, as Arkes and Blumer ([[1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0209900#pone.0209900.ref001)] p. 124) put it, the sunk-cost effect refers to the tendency “to continue an endeavor once an investment in money, effort, or time has been made”. ([View Highlight](https://read.readwise.io/read/01gma8xntje1d36jb3sk7wsvns)) ([[(Dijkstra and Hong, 2019)#^-1ba2]])