What's happening in monetary policy and macroeconomics.
I kinda wished they had included a model but it seems pretty clear that they're thinking through the lens of something like an RBC model+MP search and matching labor market. I've always liked the approach, it gets rid of the "unemployment=taking a vacation" argument against real business cycles. Your St. Louis Fed/blogger colleague was one of the first to do it if I recall correctly.
Yes, Andolfatto was well before his time in that respect. Monika Merz did related work at the same time.