Boston taxpayers benefit when nonprofit salaries get spent at local businesses, and sales taxes are collected when visitors to the city’s museums eat, sleep, and shop in the city. The US Conference of Mayors found that governments see a return on investment of more than $7 in taxes for every $1 invested in educational institutions.

From a letter to the editor by Ford W. Bell and Tim Delaney in today’s Boston Globe. Bell and Delaney write in response to an unsigned editorial endorsing Boston Mayor Thomas Menino’s plan to send mock tax bills to city nonprofits, urging them to contribute to city revenues voluntarily.

That sounds like an interesting experiment, the sending of the letters. But what caught my eye here is the claim that investments in educational institutions (presumably, higher ed institutions) lead to a “more than” 7 to 1 return on investment. Normally, I don’t actually look up studies myself to evaluate them–the point of this blog is mainly to critique how these issues get talked about in the media. But here I’m intrigued. So I’ll look up this study.

…OK, I spent my three minutes searching and can’t find it. So the methodology is going to have to remain a mystery. What we can speculate about is what these letter-writers get out of the publication of their letter. I would guess maybe <50% of those who read this letter, a tiny audience, would find it at all convincing. Factor in the hard economic times, and that number is less. Factor in how many people would retain this information, and it’s less. Factor in how many would use this information in making a decision in the real world, and the number is even less. The conclusion is that letters like this have a very low ROI.