A Twitter follower of mine just praised president Trump for saving money by donating his salary back to government departments:

“He takes a ZERO salary from the american people. How much did americans paid for Obama, Biden, Pelosi, Schumer, etc?”

Is this a significant saving for “the American people,” that is, American taxpayers? To check that, the voter must do some simple calculations. But even among those voters who can easily find the data sources and do the calculations, “rational ignorance” (as public choice economists say) will prevent most from doing it. Rational ignorance is the fact that the voter remains rationally ignorant of politics because he or she, individually, has no impact. It’s not as when he buys a car: he pays the money and gets the car he ordered. Politics and voting are very different: Why take the trouble and cost of finding information when your vote is not going to change the result of the election anyway? You’ll get the same political car anyway. Add partisanship to the mixture, and a perfect anti-Enlightenment storm is forming.

So let’s calculate if we should be grateful to the president for being so thrifty with public money. The annual salary of the president is $400,000—which means at most $300,000 after tax. This corresponds to 1/16,000,00o (one sixteen-millionth) of the annual expenditures of the federal government, which were roughly $4.8 trillion ($4,800,000,000,000) in 2019, before the pandemic struck. It can be easily calculated that in 2019 (note again: before the pandemic), the amount by which Trump increased the annual expenditures of the federal government was a bit more than $600 billion ($600,000,000,000) compared to the last year of Obama’s presidency (see https://fred.stlouisfed.org/graph/?g=vzfE).

Thus, by foregoing his presidential salary, Trump saved the American taxpayer $300,000 a year and, by the end of 2019, was spending $600,000,000,000 more of their money on an annual basis. This means that what Trump saves the taxpayers in annual salary is 1/2,000,000 (one two-millionth) of what he ended up spending over and above what Obama spent during his last year. (It is of course much worse since the beginning of 2020.)

Many taxpayers, if they knew, would have preferred that Trump ran with his $300,000 and showed frugality with the trillions of dollars of federal expenditures. According to USA Today, two previous presidents, also very wealthy, John Kennedy and Herbert Hoover, also donated their salaries. But they did not increase annual federal expenditures by half a trillion dollars.

PS: Thanks to Jon Murphy for his comments on a draft of this post.