Janet, a Walmart shop assistant in Louisiana, is so visibly stressed by working in a very understaffed store that a customer tells her she looks as if she’s going have a heart attack. Rochelle, a care worker in Newcastle, is miserable that her hours are so long that she can’t get home to put her children to bed. She also wishes she was better paid so that she didn’t owe £4,000 in catalogue bills, from buying clothes and shoes on credit for her children. Leah, a KFC worker from Richmond, Virginia, works six days a week, but is still behind on her rent and juggles calls from debt-recovery companies. Everyone in Katharine Round’s new documentary, The Divide, is struggling, trying to improve their lives; everyone is feeling the pressure. This is the reality of a low-wage existence in two of the world’s most unequal economies. Based on The Spirit Level, the 2009 bestselling book studying global inequality, the film highlights the toxic effects of divided communities on everyone who lives in them. Even the wealthy are scrabbling to stay happy.

We meet Wall Street psychologist Alden, who wants to get ahead and join the top 1% of earners, and who is working so hard to save up to move his family into a gated community that he gets home too late for story time with his daughters. When he has back surgery, he can’t afford to convalesce, and is in his office the next morning.

The Divide is the reality of a low-wage existence in two of the world’s most unequal economies

When The Spirit Level was published, it quickly attracted global attention to the ideas of its authors Richard Wilkinson and Kate Pickett. It argued that income inequality is the key cause of most modern social ills – violence, obesity, drug abuse, depression, teenage pregnancies, ill health. Ed Miliband quoted the book in a piece for the New Statesman, David Cameron referred to it in his Big Society addresses, Michael Gove said it was a “fantastic analysis”. It was the most talked-about political book of the year, but also a very dense volume that analysed vast international data sets. No one said: “This would make a great movie!”

Facebook Twitter Pinterest The finished film gives moving portraits of the lives of seven people

Apart from Round. “It was a totally mad idea to get a book of graphs and make it into a feature film,” she concedes, acknowledging moments of doubt over the years spent researching and raising money for a documentary based on a book that sweeps through 27 different countries and grapples with huge, abstract concepts of capitalism, globalisation and inequality. She persisted, raising more than £120,000 of the total budget, from a successful crowdfunding exercise.

The finished film gives moving portraits of the lives of seven people, five in the US and two in the UK, illustrating how economic division creates another division socially, with dangerous consequences for everyone. Its scope is ambitious, looking back over 35 years at the political and economic decisions that have caused the widening divide. The film races from person to person, from one side of the Atlantic to the other, giving sharp snapshots of the problems people encounter as they scrape along in economically divided nations. The documentary attempts to answer the teasing question in the film’s subtitle: “What happens when the rich get richer?”

“I wanted to cover as many social themes as the book does, but in a way that didn’t make it feel like we were talking about social themes. I wanted to put a face to things that we talk about but that are everywhere and nowhere – breakdown of society, fear of crime, rising mental-health issues. I wanted it to be very human,” Round says. She hopes to bring the issues explored in The Spirit Level to people who “probably wouldn’t read a book on inequality”.

The thesis of The Spirit Level is that life is worse for everyone in divided societies, so it makes sense to focus on the US (where the top 0.1% owns roughly the same wealth as that owned by the bottom 90% of the population) and the UK (where the 1,000 richest people own more wealth then the poorest 40% of the population).

Her film makes the point powerfully, focusing on the unhappiness of people such as Jen, from Sacramento, California, who has recently moved to a gated community (where people spend $10,000 on converting the golf carts they drive everywhere, to make them look like mini Mercedes or BMWs), and finds that her neighbours don’t talk to each other, and certainly don’t much like their children playing with hers. Jen notes that residents are planning to build a second fence within the community, to exclude the cheaper properties around the edges, and the (relatively) poorer inhabitants.

Facebook Twitter Pinterest Katharine Round hopes to bring the issues explored in The Spirit Level to people who ‘probably wouldn’t read a book on inequality’.

The film is book-ended by a clip from Barack Obama’s 2012 state of the union address, where he declares: “No challenge is more urgent. No debate is more important. We can either settle for a country where a shrinking number of people do really well while a growing number of Americans barely get by, or we can restore an economy where everyone gets a fair shot, everyone does their fair share, and everyone plays by the same set of rules.” It’s a gloomy reminder, in the run-up to the next US elections, of how little of this urgent challenge has been tackled.

The Divide weaves together footage of Margaret Thatcher beginning to dismantle the unions, and news clips from the 90s that show the emergence of billionaires, tracking a $10bn leap in Bill Gates’s fortune in the space of just six months, bringing his personal net worth up to $26bn. It sails through the corporate history of Walmart, problems with the UK’s care industry, the effects of violent crime, the three-strikes-and-you’re-out policy of the judicial system, debt, alcohol addiction in Glasgow – there’s so much here that it leaves your head spinning. You come out wanting to know more about the individuals whose lives are fleetingly opened up along this journey.

You come out wanting to know more about the individuals whose lives are fleetingly opened up along this journey

But the selected material is sharp. There is a telling bit of archive footage showing an exchange between Jeremy Paxman and a youthful-looking Tony Blair, who looks momentarily confused, then genuinely puzzled when asked: “Do you believe that an individual can earn too much money?”

“What, you mean that we should sort of ... cap their income?” he asks. “No, not really. Why? What’s the point?”

We don’t hear much from the super-rich, except a passing few insights from Richard Berman, an exhausted-looking 70-year-old venture capitalist, who offers a hilariously plaintive justification of the system: “Without big rewards, people like me aren’t going to work 15-20 hours a day in order to get rich.”

The rise of debt and the origins and consequences of the sub-prime crisis in the US are also touched on; look out for the footage of George Bush saying first: “We certainly don’t want fine print to get in the way of people owning their own homes” and “achieving the goal of a five and a half million unique minority home owners” and then a few years later, after the financial crisis, remarking sternly: “We should not help out those who made the reckless decision to buy a home they could never afford.”

Facebook Twitter Pinterest The film is book-ended by a clip from Barack Obama’s 2012 state of the union address, where he declares: ‘No challenge is more urgent. No debate is more important.’

Cathy O’Neil, a former Wall Street analyst, observes how the rise of easy credit in the past 35 years has meant “people went from pretty simple financial lives pre-1980 to the point now where people are just totally submerged in their financial accounts, and they’re all in debt”.

Disaffected banker and former vice-president of Deutsche Bank Alexis Goldstein explains: “Debt to us might seem like ‘I need a loan to go to school’ or ‘I need a loan to buy a house’ but for [my former colleagues], it is just a product that they can buy, sell and package – another way for them to get as much profit as they want.”

Goldstein’s distaste for the banking industry was bred from exposure to its entrails. “There is nothing wrong with aspiring to be comfortable. I don’t even know that there’s anything wrong with aspiring to be rich. But the aspiration of Wall Street is to have fuck-you money. Fuck-you money is the amount of money so vast that you could pick up the phone and say ‘Fuck you’ to whoever you wanted without repercussion.”

Interspersed with the frustrations of Round’s subjects is a lot of constructive anger. Care worker Rochelle says wistfully: “I wish I didn’t have to work so much. I wish I could see the kids a bit more. I don’t want much out of life. I just wish it was a bit easier.” But she is campaigning against a system that forces care workers into zero-hour contracts where they often find themselves working for less than the minimum wage.

I don’t want much out of life. I just wish it was a bit easier Rochelle, care worker

Janet explains how the corner shop she owned went bust when Walmart moved in, how she switched to working irregular shifts at the retailer, and now finds herself on the brink of eviction because she can’t afford her mortgage repayments. But we also see her standing up at a Walmart annual shareholders meeting to announce bravely: “When I think about the fact that our CEO made over $20m last year, more than 1,000 times the average Walmart associate, with all due respect, I have to say I don’t think that’s right.”

Leah, who is now working shifts at both McDonald’s and KFC to pay off her debts – also campaigns for better pay for struggling fast-food workers.

Round told her subjects that she was “making a film about the link between the economy and society and how that affected people on different levels of the income scale”. Most of them wanted to take part so that they could articulate their confusion about the disconnect between efforts they were putting into staying afloat and the paltry rewards they were reaping.

Facebook Twitter Pinterest Most people wanted to take part to articulate the disconnect between efforts to stay afloat and the paltry rewards they were reaping.

Leah (who has been too busy working shifts to view the film on the link Round sent her) says by phone from the US: “I am glad that the message got out that we are struggling.” Her take-home pay after deductions is around $150 a week for 38 hours of work. “It is never enough. I have to make do until I do better.” Her 11-year-daughter resents how much her mother has to work to earn so little. “I can’t be there for her, to help her with her homework. But the bills have to be paid and we have to eat. I have to go to work, or starve or be put out in the street,” she said.

“America is a very divided country; we’re at the bottom level. The upper class keep getting richer. Why is there such a wide gap? We are working hard, as much as we can. Why aren’t we earning enough to be able to live?”

She said she hoped people would see the film, “wake up and understand that real lives are at stake and real families are involved”.

I don’t want diamonds, furs, ski trips and all that. I just want to be able to take my baby to the movies every so often Leah, fast-food worker

“We all deserve to live and be happy. The American Dream is to have a family, a home, where you don’t have to worry about going hungry, not being able to pay your bills, or not being able to provide for your kids. It is a reachable dream if the CEOs of the companies relinquish their power and go ahead and give people raises so that they can provide for their family,” she said. “I don’t even want to be a millionaire. I don’t want the diamonds and furs and ski trips and all of that. I just want to be able to take my baby to the movies every so often.”

In Newcastle, Rochelle says she also was thrilled that her life was included in the film. “Sometimes people don’t listen to you if you’ve got nothing and you’re nobody,” she says. “I would love people to realise that you don’t have sit back; we all have a voice. I was scared, but I have a voice.”

Facebook Twitter Pinterest The film concludes that greater inequality triggers greater unhappiness.

Round is interested in the way that film can spark social change and was inspired by Al Gore’s An Inconvenient Truth, which raised global awareness of climate change, and The End of the Line, which highlighted the threat to the world’s oceans from over-fishing, and also triggered policy change. There is a very gentle call to arms in a “take action” link on the documentary’s website, which refers viewers to the charities working on this area, among them Oxfam, the Living Wage Foundation and the Equality Trust (set up by The Spirit Level’s authors).

The Spirit Level asks: “How is it that we have created so much mental and emotional suffering despite levels of wealth and comfort unprecedented at any time during human history?” Its conclusion that greater inequality triggers greater unhappiness is a useful one on which to reflect as reverberations from the Panama Papers are felt internationally, and Round is delighted that the film’s premiere comes the week after the offshore revelations have hammered home the consequences of tolerating such a divided economy. She says: “I think some people will be angry, some will be sad, some [will] think it is crazy. My main aim is that we question what is going on and that it brings more people into the debate on how we change our society.”

•The Divide UK Premiere is tonight at Picturehouse Central, in London. It is on at selected cinemas from 22 April and released nationwide on 31 May.

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