Economist: AT A sawmill in the misty hills of Michoacán in central Mexico, loggers sporting damp sombreros and droopy moustaches are working through a drizzle, hauling pine logs. With iron spikes they lever them into position, hack out any stones embedded in the pungent orange flesh and heave the logs on to a runner. A bullnecked lumberman guides them through a buzzing circular saw, slicing them into rough boards. Another cuts them into planks, which his mate tosses onto a rising stack. It barely takes …