Two economists walk through a forest and find a pile of shit
The first offers the second $100 to eat it; the second takes the $100 and eats the pile of shit
They keep walking and find a second pile
The second offers the first $100 to eat it; the first takes the $100 and eats the pile of shit
After a while the first notes that each paid the other the same $100 and feels like both just ate shit for nothing