Eating a frog

An economist and an accountant are taking a stroll in the countryside and they come across a pond. They find a frog sitting at the edge of the pond. The economist says to the accountant, "I challenge you to eat that frog. If you do, I'll give you $10,000!"

The accountant thinks about his funds and concludes he could do with some extra money, so he grabs the frog, eats it and collects the money.

A week later, they pass by the same pond, and again they notice a frog. This time the accountant challenges the economist, saying, "Eat that frog and you'll get $10,000."

After assessing the situation, the economist decides to go ahead. So he eats the frog and collects the money.

They are on their way, when the accountant says, "To think about it, we both have the same amount of money as we had before, but we both ate the frogs. How are we any better off?"

The economist replied, "What you say is true but you ignored the fact that we have been just involved in trade of $40,000."