And in almost every case, those benefits are overstated or bogus. The academic literature on this point is nearly unanimous. Brad Humphreys, who has done a number of such studies as an economics professor at West Virginia University, told me bluntly that a new stadium brings “no economic benefit.” All it does is move spending to a football game that was otherwise being spent somewhere else.

You can make an argument that the psychological uplift that the Raiders would bring to Las Vegas is rationale enough; this is a town, after all, that hasn’t had a sports team to rally around since those great Jerry Tarkanian U.N.L.V. basketball teams of the 1980s and early 1990s. And maybe the Las Vegas bigwigs backing the stadium should have just said that. Because rarely have the economic rationales for a new stadium been as flimsy as they are in the case of Las Vegas — and never has the subsidy been as high.

The wheels were first set in motion last summer when Sandoval created something called the Southern Nevada Tourism Infrastructure Committee. Its job was to chart the infrastructure improvements that needed to be made to keep tourism humming in Las Vegas. The majority of its 11 members were from the casino industry, including the president of two properties belonging to Las Vegas Sands Corp., whose chairman and chief executive is Sheldon Adelson, the most powerful man in the city. (Last year, he added the biggest newspaper in town, The Las Vegas Review-Journal, to his holdings.)

Over the years, Davis had mentioned Las Vegas as a possible relocation site. In January, after the Raiders’ plans to move to Los Angeles were thwarted by N.F.L. owners, who went with the Rams instead, some Sands executives approached Davis. The deal they eventually struck called for the Raiders to put up $500 million for a new stadium, most of which would have to come from the N.F.L., since Davis lacks the wealth of many of his fellow owners. Adelson would contribute $650 million, and the final piece, $750 million, would come from Clark County, where Las Vegas sits. What Adelson would be getting for his $650 million was not explained.

The group then went to the tourism committee, which, of course, included one of the presidents in Adelson’s company. Not surprisingly, the committee wholeheartedly embraced the stadium idea and commissioned an economic study. The study concluded — shocker! — that the combination of a small increase in the hotel tax and the upsurge in economic activity thanks to the new stadium would cover the county’s $750 million commitment. Indeed, because it was a hotel tax, the tourists would be paying, not the Las Vegas taxpayers. It was the equivalent of a free lunch.

Or was it? Getting to that number required some rather unusual assumptions. One was that a third of the 65,000 fans at any Raiders game — including preseason games — would not be Las Vegans but out-of-towners. They would stay in a hotel for 3.2 days and spend collectively, on an annual basis, $375 million. In other words, 217,000 people each year would fly to Las Vegas for the primary purpose of watching the Raiders play football. Even if there were that many seats set aside for tourists (highly unlikely), that seems implausible.

The tourism committee also accepted assumptions that the new stadium would attract a second bowl game in addition to the one it has now — and that the attendance would double. It would attract two neutral-site college football games each year. (There are usually fewer than a dozen each year.) Oh, and it would land signature events like the N.C.A.A. Final Four, the Republican National Convention and the Academy Awards ceremony (seriously).