Differences in politics and policies are largely driven not by disagreements over the right way to reach the goal, but by decisions which goals to pursue and what trade-offs are acceptable as the price.

Disagreements including this one? It sounds as though you are saying in a conversation such as this one, you are more focused on working to achieve your values than trying to figure out what's true about the world... like, say, Arthur Chu. Am I reading you correctly in supporting something akin to Arthur Chu's position, or do I misunderstand?

Given how irrational people can be about politics, I'd guess that in many cases apparent "value" differences boil down to people being mindkilled in different ways. As rationalists, the goal is to have a calm, thoughtful, evidence-based discussion and figure out what's true. Building a map and unmindkilling one another is a collaborative project.

There are times when there is a fundamental value difference, but my feeling is that this is the possibility to be explored last. And if you do want to explore it, you should ask clarifying values questions (like "do you give the harms from a European woman who is raped and a Muslim woman who is raped equal weight?") in order to suss out the precise nature of the value difference.

Anyway, if you do agree with Arthur Chu that the best approach is to charge ahead imposing your values, why are you on Less Wrong? There's an entire internet out there of people having Arthur Chu style debates you could join. Less Wrong is a tiny region of the internet where we have Scott Alexander style debates, and we'd like to keep it that way.

In my (admittedly limited, I'm young) experience, people don't disagree on whether that tradeoff is worth it. People disagree on whether the tradeoff exists. I've never seen people arguing about "the tradeoff is worth it" followed by "no it isn't". I've seen a lot of arguments about "We should decrease inequality with policy X!" followed by "But that will slow economic growth!" followed by "No it won't! Inequality slows down economic growth!" followed by "Inequality is necessary for economic growth!" followed by "No it isn't!" Like with Obamacare - I didn't hear any Republicans saying "the tradeoff of raising my taxes in return for providing poor people with healthcare is an unacceptable tradeoff" (though I am sometimes uncharitable and think that some people are just selfish and want their taxes to stay low at any cost), I heard a lot of them saying "this policy won't increase health and long life and happiness the way you think it will".

"Is this tradeoff worth it?" is, indeed, a values question and not a scientific question. But scientific questions (or at least, factual questions that you could predict the answer to and be right/wrong about) could include: Will this policy actually definitely cause the X% decrease in inequality? Will this policy actually definitely cause the Y% slowdown in economic growth? Approximately how large is X? Approximately how much will a Y% slowdown affect the average household income? How high is inflation likely to be in the next few years? Taking that expected rate of inflation into account, what kind of things would the average family no longer be able to afford / not become able to afford, presuming the estimated decrease in average household income happens? What relation does income have to happiness anyway? How much unhappiness does inequality cause, and how much unhappiness do economic recessions cause? Does a third option (beyond implement this policy / don't implement it) exist, like implementing the policy but also implementing another policy that helps speed economic growth, or implementing some other radical new idea? Is this third option feasible? Can we think up any better policies which we predict might decrease inequality without slowing economic growth? If we set a benchmark that would satisfy our values, like percentage of households able to afford Z valuable-and-life-improving item, then which policy is likely to better satisfy that benchmark - economic growth so that more people on average can afford Z, or inequality reduction so that more poor people become average enough to afford an Z?

But, of course, this is a factual question. We could resolve this by doing an experiment, maybe a survey of some kind. We could take a number of left-wing policies, and a number of right-wing policies, and survey members of the "other tribe" on "why do you disagree with this policy?" and give them options to choose between like "I think reducing inequality is more important than economic growth" and "I don't think reducing inequality will decrease economic growth, I think it will speed it up". I think there are a lot of issues where people disagree on facts.

Like prisons - you have people saying "prisons should be really nasty and horrid to deter people from offending", and you have people saying "prisons should be quite nice and full of education and stuff so that prisoners are rehabilitated and become productive members of society and don't reoffend", and both of those people want to bring the crime rate down, but what is actually best at bringing crime rates down - nasty prisons or nice prisons? Isn't that a factual question, and couldn't we do some science (compare a nice prison, nasty prison, and average-kinda-prison control group, compare reoffending rates for ex-inmates of those prisons, maybe try an intervention where kids are deterred from committing crime by visiting nasty prison and seeing what it's like versus kids who visit the nicer prison versus a control group who don't visit a prison and then 10 years later see what percentage of each group ended up going to prison) to see who is right? And wouldn't doing the science be way better than ideological arguments about "prisoners are evil people and deserve to suffer!" versus "making people suffer is really mean!" since what we actually all want and agree on is that we would like the crime rate to come down?

So we should ask the scientific question: "Which policies are most likely to lead to the biggest reductions in inequality and crime and the most economic growth, keep the most members of our population in good health for the longest, and provide the most cost-efficient and high-quality public services?" If we find the answer, and some of those policies seem to conflict, then we can consult our values to see what tradeoff we should make. But if we don't do the science first, how do we even know what tradeoff we're making? Are we sure the tradeoff is real / necessary / what we think it is?

In other words, a question of "do we try an intervention that costs £10,000 and is 100% effective, or do we do the 80% effective intervention that costs £80,000 and spend the money we saved on something else?" is a values question. But "given £10,000, what's the most effective intervention we could try that will do the most good?" is a scientific question and one that I'd like to have good, evidence-based answers to. "Which intervention gives most improvement unit per money unit?" is a scientific question and you could argue that we should just ask that question and then do the optimal intervention.