A generous man has been giving money to a beggar at a subway station for three years. One day, the beggar could not help asking his benefactor:

"Can I ask you a question?" the beggar started.

"Shoot," said the kind man.

"Why is it that you always gave me three dollars three years ago, and two dollars the second year, and now, you are giving me only one dollar?" The beggar appeared to be greatly puzzled.

"Oh," the man replied. "Three years ago, I was single. Last year, I got married, and now I have a child. I have a family to support."

"You're being very unreasonable, man," the beggar protested. "How could you spend my money on your family?"