At the start of 2011, when Tunisians rose up against their failed government, they stayed in the streets until all its key members had left. Prime Minister Mohamed Ghannouchi’s plea to retain some ministers, because they alone knew how to run the system, won little sympathy. An angry public saw no reason why any incompetents from the old regime should survive into the new.

But when Britons express similar outrage against their failed bankers, Ghannouchi’s logic still applies in force. While a few boardroom heads rolled into the safety of six-figure pensions after the crisis of 2008, most who steered the financial system to the brink of collapse are still in generously rewarded posts.

The chairman of the Independent Commission on Banking (ICB), Sir John Vickers, struck a tougher note on 22 January. He hinted strongly that the ICB’s final report, due in September, will shake up the City, with a legal separation of commercial (high-street) banks from the City-based investment banks, and capital requirements higher than the already-raised international norm.

Economists such as Sir John have redefined the subject around incentives, and believe those given to bankers after financial-sector deregulation played a large part in the crisis that followed. There were tax advantages in borrowing, so banks doubled their debt while running down the equity capital that buffered against insolvency. Deposit insurance promised to refund high-street bank depositors even if the money-managers lost it; so linked investment bankers gambled with that money until it was lost.

Pay was supplemented by bonuses when bets paid off, but not docked when they misfired. So risk-taking was diverted from a stagnant real economy into a growing financial sector.

But the financiers proved fallible in a way that now makes them unassailable. If banks are still financially struggling when the ICB gives its final report, politicians won’t want to stress them further with tighter curbs and forced divisions. And if banks are by then recovering under existing rules, there will be no political will to change these.

The bankers’ first source of power is that no one makes money unless they do. The banking system had to be rescued in 2008, at unprecedented public expense, because its collapse would have stalled the flow of payments and made asset prices spiral downwards, triggering depression. Governments across Europe are now trimming the social safety-net because of the deficits they ran up in hurriedly installing a financial safety-net.

Their second source of power is that no one makes much money doing banking the old way. Competition among high-street banks, heightened since big building societies demutualised, narrowed the traditional spread of lending over deposit rates. The retail banks responded by linking up with wholesale banks. Bigger ones, such as Barclays and RBS, expanded directly into investment banking, relying on trading bonds, shares and derivatives for a growing share of revenue and profit. Smaller ones, like Northern Rock, linked to wholesale markets indirectly, using them to raise cheaper funds than they could get from customer deposits.

Bankers would like to be viewed as technocrats – analytical experts who have moved beyond their specialism (and the call of duty) to put their managerial skills into public service. Technocrats devise solutions to problems, helping politicians choose among options – and cutting through useless debate when one option is known to be best. They innovate to make technical and social systems work better, and apply new ideas for wider public gain.

But technocrats are judged by results, and replaced when these don’t materialise. Bankers have delivered spectacularly bad results, and retain command. ‘Financial engineering’ profited its practitioners but did not produce clear benefits for others. They just picked up the bill when over-stretched machinery blew up.

Bankers now more closely resemble oligarchs – individuals who, through political as much as technical skill, take control of an important social channel and start imposing tolls. Their command over financial flows now seems no more benign than that of media and internet barons over information flows, and oil giants over energy flows. Except that big businesses can still be forced to trim their monopolies and clean up their spillages. Banks’ control of the economic nerve centres lets them pocket healthy premiums when the system works normally; and call in state-financed neurosurgeons when it breaks down.

In the 19th and 20th Centuries, technocrats sided with democrats against the threat of oligarchy. Their role models were the physicists and codebreakers whose ingenuity won wars against fas-cism, electronic engineers who built the internet, and biochemists who decoded the genome. The new century brings worrying signs of technocracy fusing with oligarchy, at democracy’s expense. Unaccountable elites made irreplaceable by publicly harnessed talent, and by strategically placed private profit, have converged in appearance and found common cause. It’s a disastrous re-concentration of talent and power that elected leaders can’t challenge.

The ICB’s brief is to promote stability and competition in the sector. That’s tricky when past competition may have contributed to instability by encouraging higher risks, and the number of players may need to be kept small to referee them effectively. Investment banks may have dragged the sector down in 2007-8, but with less intractable exposure to housing bubbles they contributed to its recovery in 2009. Failure to continue that recovery is now shackling the rest of the economy. The UK fell back towards recession in the fourth quarter not because it snowed, but because bank lending remained frozen.

Commercial banks, like many of their borrowers, are paying off debt. Until their core assets are worth more, they cannot lend more. There is increasing danger of a “doom loop”, in which failure to lend causes houses and other assets to fall further in price, eroding banks’ net worth so they have even less to lend. Manufacturers are growing only because they’ve long been accustomed to investing with retained funds, knowing that banks can’t be relied on for affordable credit. But for bankers, whose influence has long been disproportionate to their numbers, it’s a return to familiar high ground without the need to hide pinstripe beneath a wizard’s cloak.

Alan Shipman is a lecturer in economics at The Open University. He is responsible for the OU courses ‘You and your money: personal finance in context’ and ‘Personal investment in an uncertain world’.