A decade ago, the world was living in the aftermath of the worst economic crisis since the 1930s. Financial markets had stabilized, but the real economy was still in terrible shape, with around 40 million European and North American workers unemployed.
Fortunately, economists had learned a lot from the experience of the Great Depression. In particular, they knew that fiscal austerity — slashing government spending in an attempt to balance the budget — is a really bad idea in a depressed economy.
Unfortunately, policymakers on both sides of the Atlantic spent the first half of the 2010s doing exactly what both theory and history told them not to do.