BERKELEY – Neville Chamberlain is remembered today as the British prime minister who, as an avatar of appeasement of Nazi Germany in the late 1930’s, helped to usher Europe into World War II. But, earlier in that fateful decade, relatively soon after the start of the Great Depression, the British economy was rapidly returning to its previous level of output, thanks to Chancellor of the Exchequer Neville Chamberlain’s reliance on fiscal stimulus to restore the price level to its pre-depression trajectory.

Compare that approach to the expansion-through-austerity policy being pursued nowadays by British Prime Minister David Cameron’s government (with Chancellor of the Exchequer George Osborne leading the cheering squad). The country’s real GDP has flat-lined, and the odds are high that British real GDP is headed down again.

Indeed, in less than a year, if current forecasts are correct, Britain’s Cameron-Osborne Depression will not merely be the worst depression in Britain since the Great Depression, but probably the worst depression in Britain…ever.

That is quite an accomplishment. As Phillip Inman of The Guardian recently put it: "[T]he UK’s plan for recovery from the financial crisis was based on a full-throttle recovery in 2012....[C]onsumer confidence, business investment, and general spending would converge to send the economy on a trajectory of above-average growth.”

It did not work: government ministers "have done what the right-wing economists told them to do and moved out of the way – the theory being that public-sector spending and investment was ‘crowding out’ the private sector.” Instead, as Inman says, "Spain is showing the way with its austerity-driven recession. Where the weak tread, we [in Britain] look keen to follow...”

The failure of expansionary austerity in Britain should give all of its advocates around the world reason to reflect on and rethink their policy calculations. Britain is a highly open economy with a flexible exchange rate and some room for further monetary easing. There is no risk or default premium baked into British interest rates to indicate that fear of political-economic chaos down the road is discouraging investment.

There is an argument – not necessarily true, but an argument nonetheless – that, while in office from 1997 to May 2010, the Labour governments of Tony Blair and Gordon Brown overshot long-term sustainable government spending as a share of GDP. Their actions stand in contrast to countries that reduced their debt-to-GDP levels in the 2000’s, and to the United States, where the problem was not excessive spending but insufficient taxation under the Bush administration.

Yet, if one takes this view seriously, Britain, with a ten-year nominal interest rate of less than 2.1% per year, should already be in a boom. If there was ever a place where expansionary austerity should work well – where private investment and exports should stand up as government purchases stood down, confirming its advocates’ view of the world – it is Britain today.

But Britain today is not that place. And if expansionary austerity is not working in Britain, how well can it possibly work in countries that are less open, that can’t use the exchange-rate channel to boost exports, and that lack the long-term confidence that investors and businesses have in Britain?

Nick Clegg, Britain’s deputy prime minister and the leader of Cameron’s coalition partner, the Liberal Democrats, should end this farce today. He ought to tell Queen Elizabeth II that his party has no confidence in Her Majesty’s government, and humbly suggest that she ask Labour Party leader Ed Miliband to form a new one.

To be sure, if Clegg did this, his political career would probably be finished, and his party’s electoral prospects would be damaged for a long time to come. But Clegg’s political career and his party’s fortunes will be shaky for a long time to come in any case, given the economic hardship that Britain is enduring (and will continue to endure). At least defection from the ill-advised Conservative-Liberal coalition now would benefit his country.

Policymakers elsewhere in the world take note: starving yourself is not the road to health, and pushing unemployment higher is not a formula for market confidence.

J. Bradford DeLong, a former assistant secretary of the US Treasury, is Professor of Economics at the University of California at Berkeley and a research associate at the National Bureau for Economic Research. Copyright: Project Syndicate, 2012.