The real villain in the affordable-housing emergency is not avocado-eating creatives but the financial elites, according to this sobering documentary

Don’t blame gentrification for pushing the poor out of inner cities. That’s the message of this plausible investigative documentary from Swedish journalist Fredrik Gertten, who zooms out to take a global view of rising rents. The real villain in the affordable-housing crisis, his argument goes, is not avocado-eating young creatives but the financial elites. And Gertten does a decent job of delivering an economics lesson, explaining the complexities of the “financialisation” of residential real estate; most politicians, apparently, just don’t get it.

At the heart of the film is Leilani Farha, a Canadian human rights lawyer working as the UN’s special rapporteur on adequate housing. With her hippy haircut and activist approach of getting stuck in, she flies around the world talking to people affected by rising housing costs. In London, she meets Grenfell survivors and takes a tour of a former council estate torn down to make way for new luxury housing, which has been sold to investors in Hong Kong and Singapore. In Berlin, a baker has his rent put up by €600 a month.

A depressingly similar pattern emerges in countries from Sweden to Canada: a faceless company buys up undervalued properties where the poor live, fixes them up and hikes rents. In the US, Farha meets a guy whose new landlord put his rent up to 90% of his paycheck.

“They are not intrinsically evil, they are intrinsically amoral,” says the economist Joseph Stiglitz, with a grim smile, talking about the hedge funds and pensions funds maximising their wealth at the expense of people’s dignity. What can be done about it?

Farha faces an uphill battle to get anyone to listen. In what is perhaps the most heart-sinking scene she addresses a sparsely attended conference at the UN. No one is listening to her; the camera zooms in on one guy shopping for a luxury watch on his phone. So no happy endings here, but perhaps the beginnings of an international scandal?

• Push is released in the UK on 28 February.