The only surprise about Saturday's occupation of the London Stock Exchange is that it took so long to happen. No doubt the government and banking lobby was hoping that the final report of the Vickers commission last month would draw a line under so-called banker bashing in the UK. As Basil Fawlty might have put it: "I crashed the global economy once, but I think I got away with it."

So why won't popular protests go away? Here's why: there has been no public inquiry into the causes of the crash. No calling to account of those who drove the ship on to the rocks. No assertion of the public interest over financial markets. No subordination of banks to the needs of the real economy. No politician who dares face down global finance. No challenging of the defunct dogmas of neoliberal economics. No attempt to reverse the breathtaking wealth grab by the 1% at the expense of the rest.

Why should we be surprised that these protests are springing up, and why should we expect them to dissipate until these failures are addressed?

The global protest movement that started on Wall Street chose its nexus well. The current crisis of public and private debt, of unimaginable wealth for the few in the midst of falling incomes and economic insecurity for the many, springs directly from the 2008 financial crisis and the decades of deregulation and neoliberal orthodoxy that led us here.

Massive injections of public money three years ago saved the system without fixing it. A financial crisis was transformed, through bailouts, into a crisis of sovereign debt. That sovereign debt crisis is now leaking back into the financial system. Financial collapse threatens further bailouts. Public and private debt crises are intertwined.

Austerity measures are unable to break the deadlock, and in fact can only accelerate a downward economic spiral. New ways of thinking about the economy are urgently needed, that challenge the primacy of financial markets and debt-fuelled growth.

The system is broken, here's how we fix it. Don't tinker with ringfencing banks. Break them up as the first step to creating an effective local lending infrastructure. This is not pie in the sky. This is what the German banking system looks like. Its local public savings banks have supported small businesses and ordinary people throughout the recession, where big banks run away at the first sign of trouble. No annual pantomime of Project Merlin is required for our industrial competitors.

Don't create new money just to feather-bed bankers and enrich the wealthy. Create new money to create new jobs and new wealth. Use quantitative easing directly to fund the renewal of our infrastructure, to build the new green economy, eradicate fuel poverty, reskill the unemployed and tackle the climate crisis at the same time.

Don't let people become the slaves of distant creditors. It's time to talk of a massive relief of debt. The UK's problem is not really the public deficit that so obsesses the chancellor, but private household debt and the daunting treadmill that awaits a generation of young people burdened by student fees, relentless rents and a housing market that is still in the realms of fantasy.

Don't wait for money to trickle down. Experience shows that, left to its own devices, it will flood upwards. We can start by setting up local barter currencies in every city that help new enterprises use wasted land, buildings, resources and people. Ultimately we need more dispersed ownership and control of the nation's natural, human and financial capital. We need to restore large sections of the financial industry to the mutual ownership that served this nation so well until the scandalous smash-and-grab raids of demutualisation in the 1990s.

In short, we need to reassert the public interest. It turns out that, as a governing principle for the financial system, greed is not good. Financial plutocracy must give way to financial democracy – banking as if people mattered.