A swathe of Australia the size of South Korea is being razed by fire. The toll so far: 27 lives, more than 1,800 homes, a billion animals. But that’s probably a fraction of the eventual costs. Analysts who have done the sums expect a drag as much as 0.4% this quarter on an economy already stuck in second gear. Given the bushfires have consumed an area 20 times greater than a similar conflagration in 2009, the cost will dwarf the $3 billion price attached to that disaster.