Is there anything left for a documentary film to say about the financial crisis after Inside Job, Capitalism: a Love Story and Enron: The Smartest Guys in the Room? David Sington's The Flaw [2] proves that there is.

The picture draws its title from the words of former Federal Reserve Chairman Alan Greenspan, who told the US Congressional Committee: "I have found a flaw in the model that defines how the world works. I was shocked." Greenspan overestimated the self-stabilising ability of the free markets, and pumped funds into the economy whenever it showed a hint of waning; "Boosting economic activity is just a euphemism for trying to encourage consumers and businesses to borrow more," says [3] the film's executive producer Stephen Lambert.

The Flaw takes as its focal point the fluctuating level of income inequality since the 1920s, and shows through personal testimony and fluid graphics how the gap between rich and poor in the US widened immediately prior to the most recent crisis; this resulted in a situation where the majority of wealth went to a minority of citizens. That's $700bn shared among just 15,000 Americans, according to the film.

It's very lucid also on how financial inequality has reflected and exacerbated its social equivalent -- the way a moratorium historically on bank loans to African-Americans or Asians helped create ghettoes for those communities (and, in turn, shaped the largely white suburbs). I learned a lot from the film, and never felt my tear ducts were being gratuitously squeezed; when Sington does deviate from his (formidable) collection of financial experts and into case studies, there are few of the manipulative tricks so beloved of Michael Moore. Just the facts, ma'am.

That said, I could do without the supposedly comical archive material, drawn from old public information films and animation, which is used as visual punctuation to break up the sea of talking heads. You know the sort of thing -- after a sobering detail, the film will cut to a faded piece of footage in which an anonymous actor exclaims "Great Scott!" or something similar.

This is an unmistakable Moore-ism, and one which inherently patronises the audience ("We know you might be getting bored," it seems to say, "so here's something zany"). Weed out those stylistic irritations and The Flaw would be nearly flawless.

It did make me wonder, however, why filmmakers specialising in fiction have been so slow to respond to the crisis. Although there has been a slight trend in US cinema toward characters suffering economic hardship (Ryan Fleck and Anna Boden's Sugar, Kelly Reichardt's Wendy and Lucy and Meek's Cutoff, the recent Win Win, even Little Miss Sunshine), no one has convincingly translated the story of the credit crunch into a film narrative. Dominic Savage's Freefall did it rather incisively, I thought, but that was television. The British stage hit Enron [4] may have fizzled out on Broadway [5] but it may still reach cinemas, with a film version currently being developed by the producer Laura Ziskin (George Clooney is lined up as a possible star and/or director).

Where, though, are the original scripts addressing the defining catastrophe of early 21st century life?

Ryan Gilbey is the New Statesman's film critic