Cleveland Stockmeyer, one of the Seattle attorneys who unsuccessfully sued the city to block Chris Hansen’s proposed arena deal, is back with a report on what he says Seattle’s losses would be from the project. And it’s a whopping big number:

In the newly-released report, a group called Sonics Without Subsidies claims Seattle is giving away more than $731 million in subsidies for Hansen to build his SoDo arena — and they’re asking city leaders to change the deal.

$731 million is, needless to say, unexpectedly high for a project that will only cost $490 million to build total, that will only involve $200 million in public spending, and that after tax revenues and rent payments are shuffled back in forth, I’ve estimated previously would leave taxpayers with at worst a $21 million loss. So where does Stockmeyer’s hired economist come up with $731 million?

The answer, it appears, is it depends on what you mean by “loss.” Seattle’s Initiative 91, passed back in 2006 by city voters, requires that the city turn a 2.7% annual profit on any investment it makes in a pro sports facility. Under Hansen’s deal, the city would take out $200 million in bonds, which would be repaid entirely by Hansen, so there would be no cost to the city. But — here’s the catch — if you count the $200 million as a city expense, then city is getting stiffed its 2.7% annual return on investment. If you do the same math for the missing annual return on tax credits and property tax breaks Hansen would be receiving, then subtract the $92 million in land value that the city would be getting back in the deal (Hansen would buy the arena land and give it to the city), voila! $731 million!

In other words, notwithstanding the scary headlines, the “gross shortfall” that Stockmeyer’s report refers to isn’t actually money that Seattle would be giving the Hansen; it’s money that Hansen would have to give Seattle in order for the city to turn the kind of profit that I-91 required, if you count bond sales that the city doesn’t have to pay off as an “investment.”

None of this should be news to the Seattle media, since it’s exactly what Stockmeyer in his lawsuit earlier this year, though he didn’t put a dollar figure on it then. And the shoddiness of I-91’s “return on investment” formula has been established for even longer; as I wrote in July of 2012, when it was Hansen who was using bizarro math to claim that the city would rake in a ton of money from the deal:

The problem here is that I-91 was crappily written, assuming that the city would put up cash up front, and not considering that it might have to borrow money and then pay back both itself and bondholders. As a result, you have Hansen arguing that a deal in which every penny of taxes and rent payments supplied by the arena — even by his own numbers — would get poured into paying off annual bond payments is a net positive return for the city.

That was a dumb argument, and Hansen himself later backed away from it. Stockmeyer, though, seems to be deliberately confusing people about what his economic study means. To repeat: Hansen would be paying off Seattle’s bonds, and (mostly) repaying his tax breaks, but he wouldn’t pay it back and then give Seattle extra money to turn a profit on the deal as well. Whether you think this is a good deal is open to interpretation — Stockmeyer clearly doesn’t think so, two city councilmembers voted against it, and I’m on the record as being pretty meh about it, though “meh” is still better than most arena deals from where I sit. But it’s not a $731 million “subsidy” or “tax break,” no way, no how.