I'm certainly not going to argue against his point, however there's a related and more subtle one which gets ignored a lot. Generally if you are writing off su

I'm certainly not going to argue against his point, however there's a related and more subtle one which gets ignored a lot. Generally if you are writing off sunk costs there are also some accrued benefits lurking. Before you terminate X you need to look at those. Examples are things like: - Cost of restarting things like advertising in the future from a cold start. - Continuity and loyalty benefits from suppliers. - R&D realized or in-progress. - Accrued experience. That last one is a biggie. There's a reason that failing companies get new injections of capital. Quite often their major asset is that they know where the toxic slime pits in market are - because they fell into them. So, the money is gone and you shouldn't give it a second thought. But you probably bought some assets with it (plant, experience, contacts) and you should think about which ones will diminish of evaporate the moment you stop doing something. Revalue these assets in terms of the cash flow you can extract from them, write off the actual amount spent, and then you have a good basis for making the decision.