Monty Python’s Terry Jones uses puppets as a way of livening up a talking-economic-heads documentary about capitalism’s psychology-driven business cycles in “Boom Bust Boom.”

But the biggest smirks in “Boom Bust Boom,” an otherwise most informative explanation of why we should never, ever believe it when this or that generation of economists tries to explain away the possibility of a Next Great Depression (“This time it’s DIFFERENT. We have the Internet! More information, you see!”), is the presentation of John Cusack as one of the on-camera expert witnesses.

It’s a film with famous economists — some living, some dead, played by puppets — historians and psychologists, all explaining the human nature that sets us up for the cycles capitalism lives through — boom, “euphoria” driven bust, boom again.

And John Cusack. “One semester at NYU” is all the Internet Movie Database gives him, as far as credentials. But he’s got opinions, especially about the meltdown of 2007-8. And he’s outraged. So anyway.

Jones, co-writer, presenter and with his son Bill Jones co-director, takes us through the history of market-driven bubbles, from tulip mania in 16th-17th century Holland, to Britain’s “South Sea Company” government scam based on potential trade in South America, depending on how a then-raging war with Spain came out, to the Great Depression and the Great Recession.

The late John Kenneth Galbraith (in puppet form, with an actor reading from his work) intones about the “inordinate desire to get rich quickly with a minimum of effort,” the driving force behind every bubble — tulips, to market derivatives.

Every few decades, people who clamor “Let the MARKET decide,” get their way and convince the rest of us that regulating these licensed gamblers is a sin against liberty. And every few decades, they run the world economy into a ditch.

The film blasts longtime Fed Chairman Alan Greenspan as being one of those market cultists, catches him admitting he was wrong, and notes that he went on being wrong after admitting that to Congress. And thus the Great Recession was born.

On Monkey Island, off Puerto Rico, a psychologist (Laurie Santos) observes how other primates can be conned into thinking they’re getting a better deal merely by seemingly switching up the number of grapes they can buy with monkey money, creating the illusion of “bargain” when in fact there is none. Trump voters, no doubt.

The object of this short, clever blend of interviews, movie clips (“Life of Brian”) and “South Park” explanations, is to keep us on our guard, to not let the new Rick Santellis or Ben Cramers convince us “This time it’s DIFFERENT.” When it isn’t.

And besides, they of all people, don’t know. Any more than John Cusack.

MPAA Rating: unrated

Cast: Terry Jones, James Galbraith, George Magnus, Laurie Santos, John Cusack
Credits: Directed by Terry Jones, Bill Jones,Ben Timlettt, script by Terry Jones, Theo Kocken . A release.

Running time: 1:11