The people were fleeing to Egypt to avoid the taxes. There were tax evaders even back then!

Problem: People of Assyria were fleeing to Egypt to avoid taxes.

After Ahikar saw that Nadan was terrorized, he entered into the king's presence and greeted him. The king returned the greeting and made Ahikar sit down at his right side. The king said to him: "My wonderful Ahikar, behold these letters which the king of Egypt sent to us after he heard that you were slain. They have provoked us and overcome us. Many of the people of our country have fled to Egypt, fearing the taxes that the king of Egypt has sent to demand from us."

Solution: Ahikar causes Pharaoh to declare the people of Assyria to return home.

And Pharaoh arose and sent heralds to proclaim in the streets of Egypt that not one of the people of Assyria or Nineveh should remain in the land of Egypt, but that they should go with Ahikar back to Assyria. Then Ahikar went and took leave of king Pharaoh and journeyed, seeking the land of Assyria and Nineveh and he had some treasures and a great deal of wealth.