Two Lectures on Implementation Under Complete Information: General Results and the Core

What is implementation theory all about? To answer this question we shall follow Moore (1991) by describing a classic problem known as “King Solomon’s Dilemma.” As it happened, two women approached Solomon with a newborn child. Each claimed to be the child’s mother. It was up to Solomon to decide which one was telling the truth. In his wisdom, Solomon had the women lay the child before him. He drew his sword and announced that he would settle the dispute by cutting the child in half. However, just before he brought down his sword the true mother begged that he spare the child’s life and give it to the impostor. Knowing that only the real mother would be willing to give up the child rather than allow it to die, Solomon gave it to her. Such is the nature of an implementation problem which we now describe in rather general terms.