Should you be willing to:
- Work in a morally questionable part of finance in order to make large donations to charity (where you think the donations will have a greater positive impact than the harms done by the work)?
Work in a factory farm and make the conditions less bad, causing less suffering overall?
Join a political campaign you think might be harmful in order to gain connections (where you think the connections will let you have more positive impact than the harm done by working for the campaign)?
Work at a lab developing dangerous biotech so that you can blow the whistle if you see something particularly dangerous happening?
This post sets out 80,000 Hours’s views on these issues.
We look at how to analyse these situations using moral philosophy, and then apply the results to some common options, like finance, law and the oil industry. We assume you’re capable of taking the harmful option, and focus on the question: “is it right to take it?”
- We believe that in the vast majority of cases, it’s a mistake to pursue a career in which the direct effects of the work are seriously harmful, even if the overall benefits of that work seem greater than the harms.
- We think that this position is justified even if all you value, morally, are the consequences of your actions, but we also think that we should put weight on the common-sense view that the ends don’t always justify the means.
- Having said that, it’s important to bear in mind that all careers will involve some degree of negative impact. The question to think about is not whether your career involves making others worse off, but how much it does and in what way. We think you should be wary of treating classes of career paths monolithically, and instead should pay close attention to the specifics of the job in which you would be working. In the post, we’ll outline a process you can use to judge individual cases.
This article is written by Benjamin Todd, the CEO of 80,000 Hours, and Will MacAskill, a professor of philosophy at Oxford who specialises in moral philosophy.
Table of Contents
- 1 Negative impact is unavoidable
- 2 Why to avoid careers with significant negative impact, even if you’ll do more good
- 3 When might it be justified to take a job that has significant negative impact?
- 4 Case study: earning to give in finance
- 5 Which jobs might get ruled out?
- 6 Should you go into a harmful industry in order to make it better?
- 7 Conclusion
Negative impact is unavoidable
For many, the first rule of ethics is “do no harm”.
But this is not a good guide to career choice, because every career causes some negative impact.
For instance, imagine that you become a doctor with the aim of helping people. Everyone makes mistakes, so at some point you’re going to mess up, and people might die as a result. In some cases, these mistakes will be your fault plain and simple – maybe you had too little sleep, or maybe you could have studied a bit harder. But just because this scenario is extremely likely to happen doesn’t mean that it’s unethical to become a doctor.
Here’s another example. Suppose you become vegan in order to avoid hurting animals. You’ll still have to eat grains, and when those grains are harvested, typically some field mice will get killed in the process. In our modern economy, almost every action has some negative consequences.
To really minimise your negative impact, you could become a hermit and live alone in the woods. But that hardly seems like the most ethical life, because you’re forgoing huge opportunities to help others.
So, merely pointing out that a career path has negative effects doesn’t mean much, because some negative effects are unavoidable.
Another problem is that it really matters exactly how you cause a negative impact.
These days when we think of harmful careers, finance is often the first that comes to mind. But the financial sector employs almost 4% of the workforce, or 6 million people in the US.1 These people do a huge variety of tasks, from legal compliance, to IT, to trading, to banking.
First, it’s highly unlikely that all of these positions are net negative. Rather, some do harm, others do good, and many are roughly neutral.
Second, it matters exactly how the negative consequences come about. If a banker is overpaid, that may be socially wasteful and so have a negative impact on others, but ethically it’s very different from a banker who commits fraud.
When we get serious about the ethics of career choice, we cannot simply do no harm, or treat entire industries as a monolith. Rather, we should aim to:
- Compare positive and negative impact, and seek to do far more good than bad overall.
- Understand exactly what the harm consists of in the specific job at hand, and then distinguish between permissible negative impact, like the doctor making a mistake, and impermissible negative impact, like the banker committing fraud.
Career advice needs to be tailored to your situation, and that’s even more true when there’s a significant risk of doing harm.
This is what we’ll cover in this article.
Why to avoid careers with significant negative impact, even if you’ll do more good
As we’ve shown, entirely avoiding negative impact isn’t possible. But that doesn’t mean you should take a harmful option lightly, even if you’ll do more good overall by donating or other means.
Our default position is: don’t take a career for the greater good if that career directly causes significant harm.
To see why, consider this question:
Is it ethical to kill one person, harvest their organs, and use those organs to save the lives of five people?
Almost everyone agrees this isn’t ethical, at least not in the actual world we live in. And this helps to explain why we would not generally recommend taking a career that causes significant negative impact in order to do more good.
There are four reasons not to take careers that cause significant harm:
1. It probably violates rights (non-consequentialist reasons)
Many people think killing the one person is prohibited by the basic rules of moral behaviour, such as “do not kill”, which is one of the Ten Commandments.
Early modern philosophers often also appealed to basic principles of morality that would rule this out, like Kant’s categorical imperative.
Modern moral philosophers would probably focus on the person’s right to life. Killing someone against their will violates their rights, and so is probably not permissible, even if it is apparent for the benefit of more people overall.
Almost all ethicists agree that these rights and rules are not absolute. If you had to kill one person to save 100,000 others, most would agree that it would be the right thing to do (although you might still not be able to bring yourself to do it). However, they would say that such violations should only be made in exceptional circumstances.
Jobs with a large negative impact will often involve violating rights or other basic moral principles, which means that they will usually not be morally permissible on these grounds.
Later, we’ll consider which jobs in particular might be ruled out for these reasons.
2. It’s probably not the highest-impact path due to hidden harms (consequentialist reasons)
In general, effective altruists recognize that breaking moral rules against killing or seriously harming an innocent person will almost always have worse consequences than following these rules.
— Peter Singer in the Boston Review.
Other moral philosophers think that what ultimately matters is only whether your actions produce good or bad effects overall. These are called “consequentialist” theories.
These philosophers think that in principle it would be justified to kill one person in order to save the lives of five. However, they rarely think that in practice people should go around harvesting organs. That’s usually because such activities would lead to indirect harms that would make everyone worse off in the long-term. (For more detail, see the distinction between a decision procedure vs. criterion of rightness).
Turning specifically to career choice, we think there are many ways that taking a harmful job could have overall negative consequences, even if it seems higher impact in the short run (and even if you’re ‘replaceable’). For instance:
- Reputation: It’ll harm your reputation and the reputation of the people you associate with. This makes it harder to achieve good in the future. This effect could be very significant if you’re part of a social movement, such as effective altruism, veganism, feminism or environmentalism, because your actions could tar the reputation of the whole group. (And note your reputation can be ruined merely by doing a job that’s widely seen as harmful, even if it actually isn’t.)
Character: Being around unethical people all day may mean that you’ll become less motivated, build a worse network for social impact, and become a less moral person in general. That’s because you might pick up the attitudes and social norms of the people you spend a lot of time with. (Though you might also influence them to be more ethical.)
Motivation: Helping people is motivating, and a job that seems harmful day-to-day could be extremely demotivating, raising your chances of burning out.
Career prospects: The skills you learn will be less useful, because industries widely seen as harmful often shrink or perish. For instance, the earnings in investment banking went down significantly after new regulations were introduced after the financial crisis.
Advocacy: You’ll make it more socially acceptable for other people to take these jobs, and they probably won’t try to use the position for good (e.g. they probably won’t donate a large fraction of their income). This effect is most significant when (i) you’re doing something unusual and (ii) you have a large network or public platform.
There will probably be other harms, too,2 and these harms will likely offset any indirect benefits. We think that common sense moral intuitions often have important insights behind then, even if they’re not immediately obvious. All of this means that it’s usually better to avoid taking the harmful position even if you only care about the consequences of your actions.
That said, all of these factors depend on the particular situation. So although as a default we advocate caution, it’s important to analyse the details of the case.
3. Moral uncertainty
Suppose you think only consequences matter, and you’re convinced that the benefits of taking a job are larger than the harms, even taking into account all the hidden harms. Should you do it?
It’s very hard to settle ethical questions, so 100% confidence seems crazy. A survey of professional philosophers found they are very divided, and a majority are not consequentialist.3
|Answer||Number of responses|
|Other||301 / 931 (32.3%)|
|Accept or lean toward: deontology||241 / 931 (25.9%)|
|Accept or lean toward: consequentialism||220 / 931 (23.6%)|
|Accept or lean toward: virtue ethics||169 / 931 (18.2%)|
Even if you think consequences are likely all that matters, you should take into account the fact that there’s some chance that it’s unethical to ignore other considerations. And so, out of caution, you might still not want to take a harmful career. And, for non-consequentialist views, it’s clearly morally wrong to take most harmful careers. So, given our uncertainty, it seems morally safest to avoid harmful careers, as long as there are other options that allow us to do a lot of good. (Will defended this form of argument at more length in his PhD thesis).
It’s also good to take other moral views seriously so you can maintain cooperation and friendly relations with others who have those views. For instance, if lots of people in our community do things that seem immoral to many, then many people won’t want to support the community, and we’ll have less impact in the long-term. Instead, if we do things that seem good from lots of perspectives, the community can grow larger and have more influence. This is a form of indirect “moral trade” (read more in this academic paper by our trustee Dr Toby Ord).
4. Better alternatives
When we look at real examples of harmful careers, there are often nearby options that are not harmful and almost as good on other dimensions. When this is true, you may as well just take the non-harmful option.
For instance, while some areas of finance might involve deceptively marketing financial products, other parts like retail banking or venture capital seem neutral or positive. Venture capital is also very high-earning, so if you’re thinking of going into finance to earn to give, it seems better just to avoid the harmful areas.
This reason (nearby alternatives) won’t apply in all cases. Sometimes you’ll just face a sharp trade-off, but our guess is that this won’t happen very often.
When might it be justified to take a job that has significant negative impact?
We think putting the last four points together makes a good case for mostly avoiding jobs that have a significant negative impact. Doing so probably means violating rights and other moral principles, which should probably concern you even if you think consequences are all that ultimately matters (due to moral uncertainty). The net impact is also probably worse than you think due to hidden harms. Finally, there are probably better nearby alternative options to be considered.
That said, there might be exceptional circumstances in which you should take an option with serious negative impact, even if you’re not a consequentialist. For example, Oskar Schindler ran munitions factories for the Nazis, producing mess kits and, later, ammunition for Nazi soldiers, but in so doing was able to earn enough money to ensure the safety of 1,200 of his Jewish workers. He also deliberately ran the factory inefficiently, so that fewer munitions were produced. It’s hard to imagine a more unethical job than running a Nazi munitions factory, but Schindler is widely seen as a hero, and was celebrated in the movie Schindler’s List.
In an emergency, like Schindler found himself in, it can be permissible to have a significant negative impact in order to achieve a greater positive impact.
There are also clearly cases where it’s morally permissible to make individuals worse off. For instance, it’s permissible to fire an employee who’s performing badly, even though that will make their life worse. We also earlier mentioned the example of a doctor who makes a mistake.
In what follows, we’ll show how to think through these cases, and why it could be morally acceptable to work in finance, even if the industry causes a serious negative impact.
First, clarify exactly what situation you’re in
When you’re concerned about taking a job with negative impact, you could be in one of the four situations in the following table. Each situation requires a different response.
We’ve illustrated the four situations for the decision whether to earn to give in an industry with negative impact.
(We just focus on the direct impact of the work and the impact of the donations, whereas in reality you’d want to look at all the types of impact, including career capital and the indirect harms we mentioned earlier.)
|Scenario||Impact of the work||Impact of donations||Should you do the job?||Analogy|
|1 - Net harm||Large negative and morally impermissible||Small positive.||No. The net impact of taking the job is negative, so everyone agrees you shouldn’t do it.||Killing 3 people to save 1 person.|
|2 - Net positive, but morally impermissible.||Small negative, but morally impermissible (e.g. it violates someone’s rights).||Large positive.||No. Your net impact is positive, but taking the job is still morally impermissible.||Harvesting the organs of 1 person to save to lives of 5.|
|3 - Net positive, permissible.||Small negative but morally permissible (e.g. the positive effects are sufficiently large that they outweigh the negative).||Large positive.||Maybe. It depends on your other opportunities. Maybe there’s something even better.||Telling a lie to save 3 people’s lives.|
|4 - Industry isn’t actually harmful.||Positive.||Positive.||Maybe. It also depends on your other opportunities.||Saving three lives when you could have saved four.|
If taking the job is net negative, then obviously you shouldn’t take it. The job could also be net positive, but not worth taking because you have a better option.
The tricky part is deciding whether a path with net positive impact is morally impermissible or not – deciding between situations 2 and 3 above. This is what we explore in the next section.
Where’s the line between permissible and impermissible negative impact? A step-by-step process for deciding.
Perhaps the most widely practiced code of ethical behaviour is human rights. However, statements of human rights are often vague, and give little guidance on the question of when it’s permissible to violate someone’s rights, or how to deal with conflicts between them.
So, moral philosophers tend to focus on more precise notions than rights, and have invested a lot of effort in trying to precisely draw the line between permissible and impermissible harms. (You may have heard about trolley problems – this is what they’re all about.)
Here are some of the key considerations that moral philosophers have proposed to decide between permissible and impermissible harms. We think they’re a reasonable place to start when doing the analysis, although all of them are debated within the literature. If you’re a non-consequentialist, you might interpret these as morally relevant rules of behaviour. If you’re a consequentialist, you might interpret them as rules of thumb for when the indirect harms are relatively small. They’re roughly grouped into four categories, any of which can be sufficient.
- Emergency situations: Are the benefits much larger than the harms? Most agree that large enough benefits can outweigh harms. For instance, imagine an axe murderer came to your door and asked where your family is. You lie and tell him they’re out of town. Deceiving people is (usually) wrong, so was that the wrong thing to do? No – almost everyone would agree that it’s okay to lie to save the lives of your family. Protecting the lives of your family outweighs the wrong of lying. How large do the stakes have to be before it could be permissible to do harm, or violate someone’s rights? There’s no clear line, but our rough impression of the literature is that many people think it becomes unclear when the benefits are 100 times larger than the costs. Those with more consequentialist views might think that 10 times larger is already enough, while those with more deontological views might think over 1,000 times is required. Almost everyone agrees that there is some point at which the harms are immediately outweighed. (Here you also need to take into replaceability into account — if some of the harm will happen anyway, then it can bolster the case for outweighing.) The ratio of positive to negative impact can also be much smaller if one of the following conditions is true:
Are the harms intended or a side effect? Are people used as a means? Deliberately causing harm in order to accomplish a greater good is widely thought to be wrong. For instance, killing innocent people to promote a cause, like in a terrorist bombing, is wrong even if you expect to do more good in the long-term. However, if the harm is an unintended consequence, it’s more likely to be permissible. For instance, it could be justified to tolerate civilian casualties to win a war as long as you make an effort to avoid them, because, unlike the terrorism case, you don’t want to kill the civilians in order to achieve the end. This is one reason why it’s okay to be a doctor even if you’ll sometimes harm your patients – doctors don’t intend to harm their patients; the harms are an unintended side effect. If the harms are a side effect, then it can be permissible to cause a negative impact even if the benefits are only 2-5 times larger.
Do the people involved consent to being made worse off? Winning money from a friend in a poker game is not immoral, even though it makes your friend worse off. Part of this is because your friend consented to being in the game, knowing that they might lose. If you cheated, however, then this would be wrong, because the friend doesn’t consent to play against a cheater. Or if your friend was addicted to poker, then they might not be able to give true consent. With the doctor who makes an error, their patients consent to be treated in full knowledge that the treatment might go wrong. Likewise, the ratio of benefits to harms can again be much lower if both parties consent. (A non-consequentialist might even think it’s permissible to make everyone worse off if they all consent.)
Is no-one being exploited? Is the arrangement just? Both parties might gain, but if the gains go disproportionately to one side rather than another, and that side is much more powerful than the other, then it might be considered exploitation, and therefore impermissible. This could be a reason why it would be wrong to run a sweatshop factory, even if the jobs are better for the workers than what they would have had otherwise (among many other factors).
Based on the above, here’s a step-by-step process for deciding whether a job is morally permissible or not:
- Are the total benefits larger than the harms, including the hidden harms? If not, don’t do it.
Are the (counterfactual) benefits 100 times larger than the harms (or 10-1000 depending on your moral views)? If yes, then you might be in an emergency situation like Schindler, and the non-consequentialist factors are immediately outweighed.
If the benefits are between 1 and 100 times larger than the harms, check the following: Are the harms intended? Are people used as means? Do the people who get made worse off not consent? Is one group exploited? Is it unjust? If you answer yes to any of these, it’s probably best not to do it (though it still depends on the situation).
Now we’ll apply this process to some real cases.
Case study: earning to give in finance
Suppose you could take a job in finance where you’d expect to earn $200,000 per year (which is below the mean), of which you’d donate $50,000 per year to GiveWell’s recommended charities. Is this ethically permissible?
As we’ve said, finance is a huge sector, so it depends on exactly what you’re doing.
In practice, we think the people who have gone into finance to earn to give based on our advice have been careful to avoid areas with significant negative impact.
Having said that, we are concerned that people who have only had superficial engagement with our advice might have been encouraged to go into problematic areas, which is part of why we’re writing this post.
Let’s do a rough application of the steps above to finance to show we what mean.
How large are the benefits compared to the harms?
If we define the value of giving $1 to a random American as one “unit” of impact, then we think each dollar donated to GiveDirectly creates at least 20 units of impact. This is mainly because GiveDirectly’s recipients are about 100 times poorer, and money goes further the less you have. We’re using 20 rather than 100 in case there are other spillover benefits of making rich countries wealthier.
On the basis of GiveWell’s review in 2016, we think Against Malaria Foundation is about 4 times more cost-effective than GiveDirectly, and so creates 80 units of impact per dollar of donations.
This means that donations of $50,000 per year produce as much value as giving $4m to randomly chosen Americans each year, and in concrete terms would be enough to save about 7 lives per year. So the question is whether a single individual working in finance and earning $200,000 per year causes a comparable amount of harm.
In a 2013 article, we argued that for the financial sector on average, it’s implausible that the harms are anywhere near this large. It would mean that the finance sector as a whole was doing harm on the scale of killing tens of millions of people each year.
Moreover, since then when we’ve seen other quantitative estimates, they generally find that the harms are smaller than the salary. For instance, we found a rough estimate that workers in finance cause negative externalities to the American economy of about 30% of their salary, which would be ~$70,000 per year. And, as we explained, this seems more likely to be an overestimate than an underestimate, since, among other reasons, it doesn’t fully take account of replaceability.
We also made a rough estimate of the damage caused by jobs in the financial sector that increase the chance of a financial crisis, and found a figure of $42,000 per year.
This negative impact is large enough to make finance an ethically dubious career if you don’t donate to effective charities. But if you donate 25% of your income to AMF, the benefits are over 50 times larger than the harms.
However, bear in mind some caveats:
First, the estimates are highly uncertain, and only apply to finance jobs on average. If you picked the most harmful jobs in finance, they could be much worse. For instance, in the lead up to the financial crisis, certain executives in investment banks who oversaw poor lending practices probably had a far greater negative impact than typical workers. It seems plausible that many caused more harm than the good they could have done by donating their income to charity (which, by and large, they didn’t…).
This isn’t, however, an argument against finance in general. It’s possible to do huge amounts of harm in any profession, and obviously you should avoid this.
Second, a 50 times difference isn’t clearly enough to put you in an outweighing scenario, and so we still need to consider whether the negative impact is ethically permissible, as we do in the next section.
Third, we’ve ignored hidden harms.
For instance, you could have an advocacy impact, such as making it more socially acceptable for others to take the job, causing additional harms. However, going into finance is relatively common, while donating a large fraction of your income to effective charities is not. So we think the main effect of people earning to give in finance has been to encourage others to donate more, so has been net positive.
A more difficult case is with reputation. The effective altruism community has become associated with earning to give in finance, which has discouraged some people from getting involved. This could have done more harm than good (though it seems like a relatively small factor going forward).
On the other hand, we’ve ignored the possibility that some jobs in finance have a positive impact. For instance, value investors like Warren Buffett do intense research to identify undervalued firms. This brings information into the market, helping to make the price of company shares more accurate. This means companies get investment in proportion to their needs, helping the economy to grow.
Moreover, Buffett often invests after major crashes. This helps to prop up falling prices, making markets less volatile. So, it’s at least plausible that Buffett’s impact is positive, though it’s hard to say.
Are the negative impacts permissible or not?
Let’s suppose the benefits of the donations are only 1 to 100 times larger than the negative impacts of finance, so that we’re not in an outweighing situation. Then, would the path be morally permissible? Would we be in situation 2 or 3 from the table earlier?
We want to know: Are the harms intended? Are people used as means? Do the people who get made worse off not consent to it? Is one group exploited?
This depends on the details of what you’re doing.
For instance, in the lead up to the financial crisis, some people in finance sold people mortgages that they knew they probably couldn’t afford if there was a small increase in interest rates, but didn’t make these risks clear. Moreover, sometimes this was done on the back of fraudulent income statements. Besides the large economic damage this caused, these activities involved intentionally deceiving people, making them morally impermissible. They were also illegal. Here is more about mortgage fraud in the NYT. Leading banks have collectively paid over $100bn in fines due to these activities (paywall), and Goldman Sachs has admitted it defrauded investors. Here is a fascinating story about someone who tried to blow the whistle.
On the other hand, suppose you work at a hedge fund that trades the markets and makes large profits at the expense of other investors who trade frequently. This makes other people worse off, but it doesn’t seem morally impermissible. Rather, it seems more like the example of winning money off your friend while playing poker, or haggling to get a cheap product.
Moreover, most of the wealth in financial markets is held by the top 1%. They understand the risks of trading the markets and consent to taking on these risks. So if you trade against them and win, it’s hard to find a moral objection. (We have an upcoming post that looks at this in more detail.)
Some other jobs in finance are probably just socially wasteful. For instance, investors employ asset managers who don’t beat the market on average, so don’t produce any value for them. Many of these asset managers also probably don’t create significant positive externalities by making the market more efficient (though perhaps some do, like Warren Buffett as we mentioned earlier). This is a shame, but it doesn’t seem like it’s morally impermissible to take the job if you’re going to donate the money. If investors want to waste their money on useless managers, that’s okay so long as they’re not being deceived. If you then redirect these funds into socially positive activities, that’s for the better.
Are there better alternatives?
Suppose you restrict yourself to a part of finance that has neutral or small positive direct impact. In that case, we’re in situation 4 from the table.
We think it’s often not best to pursue finance to earn to give, because there are other options that have greater impact or career capital.
For instance, the expected earnings in tech entrepreneurship are similar (though higher risk), but tech entrepreneurship potentially has a greater direct impact, and likely gives you better career capital too. So, if you’re a reasonable personal fit for both finance and tech entrepreneurship, then there’s a good argument that tech entrepreneurship is better.
We also think many areas are more talent constrained than funding constrained, so if you have the skills to go into finance, it may well be better to work directly in a socially valuable organisation instead.
Conclusions on finance
It’s hard to generalise, because there are so many different types of activities within finance. Some parts seem net harmful, some morally impermissible, and some are just outweighed by alternatives. However, there are probably also options that are reasonable contenders for someone with good personal fit.
What about other common options people think are unethical, like law and management?
The situation seems very similar to finance, except that these jobs are less widely regarded as harmful, so if you think finance is permissible, then these probably are too (except in extreme cases).
It would be interesting to explore more difficult examples, such as working in the oil and gas industries.
Which jobs might get ruled out?
We made some guesses at jobs that involve causing a significant amount of negative impact. These jobs are probably ruled out since the negatives are too great compared to the benefits, even if you donate. Some might also be morally impermissible for non-consequentialist reasons.
- Marketing and R&D for compulsive behaviours such as smoking, alcoholism, gambling, and payday loans (and see this post on being a tobacco CEO)
- Factory farming
- Fraudulent medicine
- Patent trolls
- Lobbying for rent-seeking industries
- Weapons research
- Activities that make financial firms highly risky
- Fundraising for a charity that’s less effective than average
- Forest clearing
- Tax minimisation for the rich
Bear in mind that the list isn’t (yet) the result of thorough research, and any of the above could easily be wrong. Making good estimates of the size of the harms and benefits is very hard, as is analysing the ethics of the situation.
Should you go into a harmful industry in order to make it better?
For instance, could it be justified to work on a factory farm for a year in order to publicise the conditions, or develop better welfare standards that could be applied across the industry?
This is a tricky situation, and should not be pursued without a lot of thought. Our main advice is to be cautious and seek advice from people with an outside perspective.
When might it be justified? Applying what came earlier, one situation might be outweighing – if the benefits are expected to be much larger (at least 100 times) than the harms. This seems plausible with the example suggested above.
Second, it seems more acceptable if you can work in a position that doesn’t directly harm the animals, since then the harm seems more like a side-effect, rather than intentional.
If you’re considering taking a career with negative impact, you probably shouldn’t, for a few reasons.
First, there are likely to be better alternatives. Second, the option is probably less positive than it first looks, due to hidden harms. Third, even if it’s net positive, you probably shouldn’t violate common standards of morality due to moral uncertainty. Even if you mainly care about the consequences of your actions, it’s worth putting some weight on the common sense position that the ends don’t justify the means.
However, that doesn’t mean you should never take a career with negative impact. In exceptional circumstances, it might be justified, such as when the benefits outweigh the harms by more than 100 times (or 10-1000 times depending on how consequentialist you are). It also be justified to cause the negative impact even if the benefits outweigh by a much smaller factor, say 2-5 times, if the harms aren’t morally problematic, like being an overpaid asset manager.
That said, if you are considering taking a harmful job, be really cautious, and explore all the arguments before you go ahead. Much comes down to the details of the situation, so you need to make a case-by-case analysis.
Read more research like this in our advanced guide:
You might also be interested in Considering Considerateness, an article by our sister charity, which argues that people who want to do good should aim to be extremely considerate of others, and presumbly, not take jobs that are widely seen as harmful.