I posted this in response to some discussion at Crooked Timber on the Iraq war, Gaza and so on.
Looking at the discussion, it seems as if nearly everyone is concerned about the (foreseeable) consequences of their actions, but there are a lot of claims that some consequences should be treated differently from others (intended vs unintended, direct vs intermediated by the predictable reactions of others, and so on).
To an economist, what this naturally suggests is the possibility of moral arbitrage.
Opportunities for arbitrage arise when the same good (or financial asset, or moral consequence) is priced differently in different markets. Someone who can buy in a market where the good is cheap and sell where it is dear has the opportunity for arbitrage profits.
So, if you want to raise the moral value of a particular action, what you need to do is make sure that the positive aspects of the action are valued in markets where the price is high, and the negative aspects where the market is low. For example, an advocate of the Iraq war can be a virtue ethicist as regards their own heroic standard against Ba’athist dictatorship, a deontologist regarding obligations to punish the criminal behavior of their enemies, regardless of the unintended effects on the millions of people living in the general vicinity, and a consequentialist regarding the necessity to excuse the criminal behavior of their leaders for fear of subsequent bad effects on the polity.
As this example shows, with arbitrage opportunities, all sorts of things can be made possible. A consistent virtue ethicist (for example, a Jeffersonian) might reasonably conclude that the criminal behavior inevitable in a long occupation of a largely hostile country is unacceptable to someone who wants to maintain a virtuous disposition. A deontologist would object to violations of well-established principles of just war theory. A consequentialist would certainly conclude that the foreseeable costs of a war exceed the benefits. But a moral arbitrageur can mix and match these principles to reach a conclusion none of them would individually support.
The trolley-crash toy examples seem perfectly designed to encourage moral arbitrage of various kinds. By shifting consequences between direct and indirect, intended and unintended, close and remote, it seems as if moral virtue can be claimed for any course of action you like.