Gender norms and tax forms

This is one of those posts where I have to stress from the get-go that correlation does not necessarily imply causation and that readers should please, please not take this stuff seriously.

The reason why I start with this bold disclaimer is because this research paper by officials from the US Treasury and academics from the University of Michigan makes some bold statements.

In their research, they looked at US income tax returns filed jointly by married couples. Like in most countries where married couples can file a joint tax return, one completely irrelevant choice they can make is which name to put first, the husband’s or the wife’s. It doesn’t matter which spouse comes first but in the vast majority of cases, it is the husband’s name that appears first. However, the share of tax returns with the husband’s name first is declining steadily because more and more couples that start to file jointly choose to put the wife’s name first.

Share of income tax returns with the wife’s name first

Source: Lin et al. (2023)

I think the reason why the ratio of women named first is rising is pretty straightforward. It is changing gender norms. Traditionally, in Western marriages men were in charge of household finances and were most likely the ones who filled out the tax returns. And when you fill out the tax return, there is an implicit tendency for us to put the name of the person who fills out the return first.

But nowadays, there is an increasing number of marriages where women make more money than men or where women are filling out the tax returns and they may simply put their names first on the form.

If this explanation of name orders based on gender norms is correct, one should be able to find all kinds of correlations with political attitudes. Indeed, while there is an increase in female-first tax returns in every state of the US, the states with the highest ratio of female-first forms are states like Vermont, Washington State, or Washington DC. All of them tend to be more Democrat-leaning. Meanwhile, the states with the lowest share of female-first returns are states like Iowa, North Dakota, or Utah, all Republican-leaning.

But whose name comes first on the tax return isn’t just correlated with political voting preferences but also with things like views on abortion (correlation 0.73) or fraction of people self-identifying as highly religious (correlation 0.7).

Plus – and this is where I think the disclaimer above becomes very important – tax forms where the man is named first tend to cheat more on their tax forms. Again, correlation is not causation. Not all men who fill out tax forms and not all women who fill out tax forms are completely honest. It just so happens that men tend to take more risks in all areas of life and part of that risk-taking attitude may be that they try to ‘nudge the numbers’ on their tax forms to their advantage. Meanwhile, women on average tend to be less risk averse so they also tend to avoid such risks on tax forms.

The end result is a study where one does find a correlation simply because one looks hard enough and crunches the numbers long enough. Do the results matter or should we learn something from the results? I think the only thing we should learn from studies like this is that not all studies need to be taken seriously. And just because you can find correlations between two sets of numbers, these correlations don’t necessarily mean anything.