That’s all very well in practice, but how does it work in theory?
— old University of Chicago joke
I expect this blog’s readership to demand the theoretical considerations, so here’s a (non-exhaustive) compilation, beginning with a setup anecdote:
In December of 2007 I was briefly—very briefly, as the work was interrupted by a blizzard—involved in rebuilding in Greensburg, Kansas, which had been practically erased from the map seven months earlier by an immense tornado. I had driven through a couple of months after the event and stumbled into a photo-op for Sen. Pat Roberts, who was doing a ribbon-cutting of sorts in a brand new convenience store. The devastation was more impressive than his speech; indeed, people who worked both New Orleans after Katrina and Greensburg after the tornado typically remarked that, allowing for scale, Greensburg was worse.