New data from the United Kingdom indicates that its economy has seen six consecutive months of economic contraction—the rule of thumb definition of recession.

The lesson here should be pretty plain: this is the utterly predictable (and predicted  in real time) result of these policies.

Let’s be even more concrete: If the U.K. had just followed the fiscal stance of the United States over the past two years, they would not have re-entered recession. Adam Posen of the Bank of England recently estimated that the U.S. fiscal stance has contributed about 3 percent extra to overall GDP growth compared to a scenario where they had followed the U.K. stance. And this gap has actually widened in more recent years (and is projected to widen even further for 2012).

Posen’s estimate crucially includes the drag from state and local governments in the U.S., so it’s not like this overall fiscal stance in the U.S. over this time has been wildly expansionary. Just matching the U.S. fiscal support over this time period would have been a pretty modest goal.

But of course, this goal was rejected by the conservative government elected in mid-2010, and instead the U.K. has followed a plan based on austerity.

There is plenty to lament in policymaking responses to the crisis of the past four years, but the U.K. fiscal tightening may well be the single most avoidable own-goal over the period. Greece, for example, really can’t run expansionary fiscal policy right now (at least not without help from the core countries of the eurozone) without getting savaged by bond markets that will push up interest costs on debt.

The U.K., on the other hand, faces no such constraints. They print their own currency so they cannot be forced into default by bond markets, and there has been no upward pressure at all on their debt-servicing costs since the Great Recession began (see chart below). There is, in short, no actually-existing macroeconomic problem that austerity addresses. Instead, the swing towards it has been driven by ideology. And it has not turned out well.