I just posted this to LessWrong.
A trolley problem is something that's used increasing often in philosophy to get at people's beliefs and debate on them. Here's an example from Wikipedia:
As before, a trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by dropping a heavy weight in front of it. As it happens, there is a very fat man next to you - your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed?
I believe trolley problems are fundamentally flaws - at best a waste of time, and at worst lead to really sloppy thinking. Here's four reasons why:
1. It assumes perfect information about outcomes.
2. It ignores the global secondary effects that local choices create.
3. It ignores real human nature - which would be to freeze and be indecisive.
4. It usually gives you two choices and no alternatives, and in real life, there's always alternatives.
First, trolley problems contain perfect information about outcomes - which is rarely the case in real life. In real life, you're making choices based on imperfect information. You don't know what would happen for sure as a result of your actions.
Second, everything creates secondary effects. If putting people involuntarily in harm's way to save others was an acceptable result, suddenly we'd all have to be really careful in any emergency. Imagine living in a world where anyone would be comfortable ending your life to save other people nearby - you'd have to not only be constantly checking your surroundings, but also constantly on guard against do-gooders willing to push you onto the tracks.
Third, it ignores human nature. Human nature is to freeze up when bad things happen unless you're explicitly trained to react. In real life, most people would freeze or panic instead of react. In order to get over that, first responders, soldiers, medics, police, firefighters go through training. That training includes dealing with questionable circumstances and how to evaluate them, so you don't have a society where your trained personnel act randomly in emergencies.
Fourth, it gives you two choices and no alternatives. I firmly reject this - I think there's almost always alternative ways to get there from here if you open your mind to it. Once you start thinking that your only choice is to push the one guy in front of the trolley or to stand there doing nothing, your mind is closed to all other alternatives.
At best, this means trolley problems are just a harmless waste of time. But I think they're not just a harmless waste of time.
I think "trolley problems" are commonly used in real life to justify tyranny and oppression.
Here's how it goes:
Activist says, "We've got to take from this rich fat cat and give it to these poor people, or the poor people will starve and die. If you take the money, the fat cat will buy less cars and yachts, and the poor people will become much more successful and happy."
You'll see all the flawed I described above in that statement.
First, it assumes perfect information. The activist says that taking more money will lead to less yachts and cars - useless consumption. He doesn't consider that people might first cut their charity budget, or their investment budget, or something else. Higher tax jurisdictions, like Northern Europe, have very low levels of charitable giving. They also have relatively low levels of capital investment.
Second, it ignores secondary effects. The activist assumes he can milk the cow and the cow won't mind. In reality, people start spending their time on minimizing their tax burden instead of doing productive work. It ripples through society.
Third, it ignores human nature. Saying "the fat cat won't miss it" is false - everyone is loss averse.
Fourth, the biggest problem of all, it gives two choices and no alternatives. "Tax the fat cat, or the poor people starve" - is there no other way to encourage charitable giving? Could we give charity visas where anyone giving $500,000 in philanthropy to the poor can get fast-track residency into the USA? Could we give larger tax breaks to people who choose to take care of distant relatives as a dependent? Are there other ways? Once the debate gets constrained to, "We must do this, or starvation is the result" you've got problems.
And I think that these poor quality thoughts on policy are a direct descendant of trolley problems. It's the same line of thinking - perfect information, ignores secondary effects, ignores human nature, and gives two choices while leaving no other alternatives. That's not real life. That's sloppy thinking.