The U.S. Olympic Committee announced today that it’s killing Boston’s bid for the 2024 Olympics, after a few days in which the two key local political players — liberal mayor Marty Walsh and moderate Republican governor Charlie Baker — were hesitant to support the bid without further study. The two had important public-policy concerns (Walsh supported the idea but the proposed bid, which promised no cost to taxpayers, had barely been studied), and the Massachusetts public opposed the idea by a healthy margin. The USOC demanded that they commit to it by the end of the day today (they have to present the bid on an international stage by mid September); Boston stood strong.

This one event is good news for Boston, but it reflects a couple interesting larger developments: If even Boston, a sport-crazed city with a taste for big government, rejected this, maybe the mood is shifting against taxpayer-funded sports boondoggles. There’s mounting public-policy research showing that both stadiums and big events are a bad economic deal, and the worsening health of state and local finances has also made them look a bit more unwise. (On the other hand, sometimes it’s especially struggling cities that hope to revive their economy with such a project, and the number of them hasn’t diminished.) The rapidly rising cost of these projects, no doubt goosed in part by taxpayer financing, also surely hasn’t helped.

But deep-blue Boston in particular may have learned its lesson while back, from the Big Dig – a lot of gargantuan public projects, wherever the money comes from, end up costing more, creating more disruption, and delivering fewer benefits than expected. The Big Dig’s two decades of disruption and $24 billion spent have given Boston, um, a quicker ride to the airport, a flashy bridge, and a well-intentioned but largely barren public space between downtown and the waterfront where an elevated highway used to be. Among other promised benefits, the Olympic bid proposed to take another misused piece of real estate — a highway-enclosed industrial area called Widett Circle — and put it to better use, while handing huge tax incentives to a few developers. I’m all for redevelopment, but gradual liberalization and improvement is generally the way to do it, not grand projects, pushed by unaccountable bureaucrats, sold on different premises. That may not be lost on Boston, which hasn’t been prone in recent years to the kind of ridiculous megaproposals other liberal northeastern cities occasionally come up with (viz. Governor Andrew Cuomo’s $4 billion proposal to tear up LaGuardia and add a ferry dock).