Mayor Bill de Blasio likes to say that there’s plenty of money in New York City, but that it’s in the wrong hands.

Chirlane McCray’s, perhaps?

The first spouse went before the City Council Tuesday — tripping spectacularly over her own tongue while removing any doubt that her billion-dollar husbandly indulgence, ThriveNYC, amounts to an epic public policy swindle gussied up as a mental health program.

Still, questions linger.

Such as, how did it happen that Thrive burned through more $565 million over four-plus years to no appreciable good effect with nobody noticing?

Certainly not the City Council, a legislative body comprising 50 stuffed cabbages and a speaker who wants to be mayor — a fellow who stood by incuriously as the city’s streets and subways slowly filled with insane people, many of them threatening and dangerous.

The council redeemed itself only slightly Tuesday, asking McCray — too politely for the circumstances — to explain herself, and then settling for a non-answer answer for the ages:

“ThriveNYC was my idea,” she said. “I’m the founder, I provide the strategic support, I hold meetings on behavioral health and I amplify things to the public.”

Well, yes. And then what?

One can only imagine what a mad scramble those meetings are. With a quarter of a billion dollars (!!) to divvy up every year, one easily could get an arm broken when the boodling begins.

Anyway, for details the mayoral missus deferred to one Susan Herman, who “does the day-to-day management and makes the decisions.”

Turns out that ThriveNYC director Herman had no more firm a grasp on detail than did McCray — telling the hearing that her agency employs 400 benchmarks to measure effectiveness — but that “all of those metrics are being refined.”

A never-ending process, no doubt.

More telling was that neither Herman nor McCray could even tell the council how many people are on Thrive’s payrolls — though surely there are many.

And just as surely, jobs are the point — both municipal positions and employment with the numberless, anonymous, unaccountable and usually politically connected not-for-profit agencies that live off city dollars.

For, clearly, the objective can’t be services.

Council members learned Tuesday that only $30 million of Thrive’s $250 million annual budget — an anemic 12 percent — is spent on the seriously mentally ill, with the remainder of that enormously expensive burden shunted off to the city’s more traditional social services agencies.

(And don’t forget the Department of Correction: A huge but ultimately unknowable percentage of New York’s mentally ill reside on Rikers Island and in other lock-ups.)

But in the end, McCray insisted Tuesday, all the spending is to the benefit of every New Yorker.

“The reason I say that all of Thrive’s budget is tailored to [all city residents] is because it’s very difficult to say [what] is the percentage of our population that is seriously mentally ill,” concluded Mrs. Mayor — without laughing.

Her performance left council members blinking.

“We know as little about the program after the hearing as we knew before the hearing,” said Councilman Ritchie Torres (D-Bronx). “There is no evidence it’s working.”

On Wednesday, councilmembers were huffing that de Blasio has been showering his wife with tax dollars with embarrassing results. This seems laughingly obvious, except that this is Gotham and Mrs. Mayor may simply be fronting her program’s principal beneficiaries — the municipal unions and the nonprofits.

Meanwhile, just as Torres sees no evidence of Thrive’s efficacy, there’s no reason to believe he’s willing to do anything about it.

“If there’s a program that’s been found to be ineffective, we should pull the plug,” he said Wednesday. “If there’s a program that’s been found to be effective, we should continue it.”

Given that nobody seems to know how many programs there even are, it’ll be a while before McCray’s allowance is cut off. She’ll be happy; the mayor will be delighted — and the unions and nonprofits will be delirious.

It’s crazy, but it’s New York.

Bob McManus is a contributing editor of City Journal. bob@bobmcmanus.nyc