The best-known theory on this topic is that money can buy happiness, but only up to a point. This comes from a study by two Nobel Laureates, Daniel Kahneman and Angus Deaton (2010), which found that emotional wellbeing rises with income. However, it rises logarithmically. That is, as an individual's income increases, their wellbeing increases at a slower and slower rate. And after income surpasses about $75,000 per year, Kahneman and Deaton's data suggests, wellbeing stops increasing altogether.
However, new research by Matthew Killingsworth (2021) challenges this finding: the paper, entitled "Experienced well-being rises with income, even above $75,000 per year," gives us reason to think that we should take a closer look at the link between money and happiness, with an important caveat. As we argue in this piece, a more accurate title for this paper might be: "Money barely increases happiness above $75,000 per year — unless you really value money, and even then not by much."
In 2010, Kahneman and Deaton's study examined the link between income, emotional wellbeing, and overall life evaluation. Kahneman and Deaton's study relied on a survey of 450,000 American respondents that contained questions about emotional wellbeing, life satisfaction, and reported family income. After examining the data, the pair famously concluded that happiness remains basically unchanged once household income exceeds $75,000, though overall life evaluation keeps improving. The key conclusion is that incomes over $75,000 buy life satisfaction, but not happiness.
Conversely, Killingsworth’s recent study takes advantage of technology to revisit the relationship between income and happiness. The new study used a smartphone app to periodically ask a large sample of people how they felt throughout the day on a continuous scale from “very bad” to “very good.” By contrast, the 2010 study asked people to recall how they felt in the past. As Killingsworth points out, the 2010 study’s methodology is “vulnerable to memory errors and biases in judgement.” Contrary to Kahneman and Deaton’s study, Killingsworth found that happiness and life satisfaction continue to increase with household income, even after income surpasses $75,000.
Does that mean that money makes a big difference in happiness and that you should go work at Goldman Sachs? Not so fast. Note that Killingsworth’s graph uses a logarithmic x-axis for income (echoing Kahneman and Deaton 2010) and the y-axis uses z-scores, a measure of standard deviation that won’t have much intuitive meaning to anyone unfamiliar with statistics. Here’s the data for experienced wellbeing, but plotted with different axes.
While it is true this paper finds money is correlated with happiness for incomes past $75,000, we should be careful not to overinterpret this evidence. (Obligatory note: correlation does not imply causation.) The association is quite small — perhaps underwhelmingly small — and a large part of the explanation is driven by whether people believe (or have learned) that money matters to them. So, it might be better to say: money can buy happiness, but you might be surprised at how little it buys.
The previous point raises the question: doesn't it matter how people spend their money? Surely there are better and worse ways to spend it. A great paper on this topic is If money doesn't make you happy then you probably aren't spending it right. In it, the authors make the following suggestions:
As you might expect, we want to focus on the happiness from helping others. There is some evidence that prosocial spending (i.e., spending money to benefit others) improves the spender's happiness. In one experiment, participants were given money and then randomly told to spend it on themselves or others. As it turns out, those who spent it on others reported higher levels of happiness at the end of the study.
So one reason to give is that it will probably make you happier than the other ways you could spend your money, especially if you're already earning a lot of money.
The other (probably bigger) reason is that it can substantially increase the happiness of others too.
Killingsworth's study suggests that doubling Jane's income from $500 to $1,000 increases Jane's happiness by the same amount as doubling John's income from $100,000 to $200,000 increases John's happiness. However, that $100,000 increase for John could instead be used to increase the happiness of 200 others like Jane by the same amount. That's quite a bargain!
Killingsworth's study has advanced our state of knowledge on the link between money and happiness through the use of a clever research design. The new data suggests that increases in happiness don't stop after an individual reaches an income of $75,000. Instead, the increases continue, and perhaps plateau, at a later point. However, this new insight doesn't significantly change the conclusions drawn after Kahneman and Deaton's 2010 study. It seems that chasing ever-increasing amounts of money is an ineffective way to find happiness for ourselves. On the other hand, giving to highly effective charities is a great way to make others feel happier. Those of us who live in high-income countries have an exciting opportunity to significantly improve the lives of others by pledging to donate 10% of our income over the course of our careers. Even better, we might find ourselves much happier while doing so.