Opinion: in his latest column, Kieran Long argues that the causes tech billionaires donate their money to "tell us what they are scared of" and what the design challenges of the future are therefore likely to be, and asks whether designers and architects are prepared to go along with these visions.

In my last piece for Dezeen, I wrote about how designers had lost sight of their bigger responsibilities, that few of them really had any view on how their work might shape society and people's lives. I hold to this. But just as in the post-war period it was designers and architects making the running, it is now technology businesses and their design engineers and coders who are proposing all-embracing futures that seem plausible, visionary and utopian to those in power.

It has always been part of a designer's role to imagine a world succeeding this one, a world improved (or otherwise) by a problem solved, or a situation poetically composed and made useful. As design has run scared of this role, it has been the scions of technology that have taken up the mantle of prophets of the world to come. The leaders of The New Digital Age (as Google’s Eric Schmidt and Jared Cohen christen it in their recent book) are leading us into a new world, not just towards new ways of making money. It's important that designers and architects pay attention to the futures they are proposing. Are you ready to go along with these engineers and entrepreneurs? Will you solve the problems they think need solving?

Tech billionaires and near-billionaires give us clues to the future in ways that are more personal, and perhaps more truthful, than the rhetoric they spout to shareholders and sell to the world through vanity publishing. I've become interested in how their philanthropic causes tell us what they're interested in, what they are scared of, what the design challenges of tomorrow will be.

The rich have always sought ways of making it feel ok to be stinkingly, lavishly better off than everyone else. They need somewhere to put their money that makes them feel less evil: to be patrons rather than jealous, scrooge-like hoarders. Historically, philanthropically inclined fat cats have invested most of all in their own immortal souls: see the patrons of countless renaissance churches. But basilicas are out of fashion, and what the Medici of the new economy are spending it on is facsinating, and seems to be changing as the generations of tech billionaires come and go.

Bill Gates (58) is the leader of the first generation of tech billionaires, who are old enough to hear mortality whispering to them as they lay awake at night. Microsoft might enjoin us to "Be What's Next" (in the words of their recently dropped marketing slogan), but its founder now works full time with his Bill and Melinda Gates Foundation on big ticket causes. The foundation's money is spent trying to solve global problems around "extreme poverty and poor health in developing countries". Gates is trying to prevent an immediate future that involves the third world succumbing to what the west might consider nineteenth-century acute diseases.

Eric Schmidt, executive chairman of Google, is exactly Gates' age and his beer money is spent mostly on environmental causes. The main charitable vehicle for Schmidt’s fortune is the wonderfully doomy sounding 11th Hour Project. Hard to square the techno optimism of The New Digital Age with the idea we are mere minutes away from eco meltdown. It's easy to be flippant about their projects, but you can’t accuse Gates and Schmidt of avoiding the big questions, even if their company lines are more optimistic about the future than their charitable activities suggest.

The generation younger than this is perhaps more interesting, even though the beneficiaries of its largess are from the first world. It might be uncharitable to call Amazon founder Jeff Bezos' (49) recent $250 million purchase of the Washington Post philanthropic, despite the chronically declining market for print media, but it is at least non-core business. Bezos "vowed to continue the newspaper's long history of independent journalism" when he closed the deal in September. A couple of weeks later, eBay chief Pierre Omidyar (46) announced he would plough $250 million into an online investigative journalism venture with editorial help from former Guardian journalist Glenn Greenwald, the man who broke the stories of the NSA's and GCHQ's surveillance programmes.

These forty-something businessmen, whose fortunes come from creating ringfenced online marketplaces that behave like monopolies, seem sincerely passionate about preserving the freedom and independences of the press. It's fascinating that an Iranian-American tech billionaire like Omidyar would invest a fortune backing the activities of a journalist that some in the US or British governments consider a traitor. I think the radicality of that has been underrated. We can not yet know how these two embryonic media barons will behave, but they have identified the very real risk of a future without a free press. They are investing in a part of civic society that the market can no longer guarantee.

The generation younger than them is not yet at the stage of deciding which of the world's big problems to solve. Yes, Facebook boss Mark Zuckerburg (29) has given away a fortune, reportedly to educational causes in America. But it's more fascinating to observe those whose views are in formation, who have not yet committed to any ethical, big-picture causes. The insight into Twitter co-founder Jack Dorsey (36) given by the New Yorker's extraordinary profile of him last month points to a rather frightening prospect.

Dorsey comes across as introspective, gnomic, obsessive to the point of autism about data and a pseudo-profound intellectual dilettante about most other things. He's somewhat in the mould of a clove-cigarette-smoking mature student: hippy-ish, but without the ideals or background sense of community. The New Yorker reveals him as committed to nothing you could call a cause. Dorsey considers Twitter "neither liberal nor conservative; it’s a public utility, like water or electricity."

"I like technology that is unbiased," he says.' His future is one of cold, hard data, made as free and available as possible.

What does someone like this do when the time comes to spend what is already pretty much limitless wealth? Dorsey's world sounds rather lonely and calculating, and while the New Yorker describes him as liberal and progressive, he sounds to me like someone unmoored, with very little sense of the collective. What will he see as his responsibilities when he has to spend his billions? What will happen when this younger generation of Californian, venture-capital-backed, neoliberal rich decides that its money must not just accumulate, but be made to do good? How can a 36-year-old billionaire, who without irony can say that "the most fundamental issue is economic equality", possibly make his money seem less evil to him? I'm betting on two outcomes: either he starts a religious cult, or he gives on the hippy shit and just ploughs on with accumulating more cold, hard cash. Whatever Dorsey and his like decide will have an impact on all of us.

What would you tell him to spend his money on if he asked you? Culture? A free press? Third World development? Or something else? I think design and architecture should have an answer for these questions, just as the architects of the renaissance did when the Medici came calling. Spending a billion dollars requires real imagination. Dorsey has it, and he doesn't know what to do with it. What would you design for him if he asked?

Image of money is courtesy of Shutterstock.

Kieran Long is Senior Curator of Contemporary Architecture, Design and Digital at the Victoria & Albert Museum. He presents Restoration Home and the series The £100,000 House for the BBC, and is currently the architecture critic for the Evening Standard newspaper.