What Part of "Nine Sacks of Ears" Don't You Understand?

One of the central issues of information economics is the problem of “signaling”—how and when can you deliver an assurance to your bargaining partner that your message is accurate and reliable? At the Battle of Liegnitz in Silesia on April 9, 1241, the Mongol descendants of Genghis Khan seem to have come up with a workable solution:

In this horrific battle the Mongols defeated the Europeans completely—on their own terms—and virtually annihilatd them. Duke Henry [Henry II the Pious of Silesia] was killed trying to escape with a handful of men, and the Mongols sent nine sacks of ears to [their commanders] Batu and Subotai in Hungary to show them the extent of their victory.

So Erik Hildinger in Warriors of the Steppe (1997) at 144. Hildinger adds that “Duke Henry’s head was set on a pike and displayed befor the walls of Liegnitz,” which is a gesture with a certain signaling value all its own.