If I have a load of grain, and a load of people half way across the world really need grain to live, and I agree to sell them the grain - I agree a price taking into account my a) transportation costs, b) productions costs and c) required profit - then they get their grain, I get my money, everybody is happy.
But say I pack all this grain up on a boat, it gets half way across the ocean to its destination, then I get a phone call saying, for whatever reason, 'we can't pay for your grain' then I'm in the shit. I have a load of grain but no buyer. They have a need for grain, but no money. What do I do?
Well, I could try and find an alternative buyer, which would solve my problems, if not those of the people who needed the grain to live in the first place. Except my grain is half-way across an ocean so unless I can find a buyer near to where the boat was headed then further increases in transportation costs, given my grain has a value dictated by markets, would likely mean I would lose money. I don't want to lose money.
So I get my abacus out and add it all up. I could try and find a buyer elsewhere within the global village, except the price I would get + the cost of getting it there + the costs I have already accrued mean this would lose me a lot of money.
The other option is that I could cut my losses and forget any prospect of making money from my grain. My abacus tells me that I would lose less money this way than if I sought an alternative buyer. But how do I gut my losses?
I could send the boat on to its destination and give the starving people - who were going to buy my grain - the grain for free. Except that would mean paying for the boat to continue its journey, heavy with grain, until it reached its destination, then paying for the boat to come back again.
Or I could order the cargo hold to be opened and all that life-saving grain can fall to the sea-bed instead. That way I only have to pay for the boat to come back, light and empty, across half an ocean. I've lost money, but less than I would have lost had I taken either of the first two options. I've taken the sensible business decision. That there are people in desperate need of grain doesn't really enter my thinking. This is a business, not a charity.
It was the rational decision under capitalism.
And this parable is why capitalism is wasteful.