Communal farming is similar. The Pilgrims tried shared farming when they first arrived in America. But, rather than working shared property, they faked illness. Some of them said the kids were too young to go out in the fields. The Pilgrims nearly starved to death, and ended up eating rats, dogs, horses and cats. When each was given his own land on which to grow crops, food was abundant. I wish they taught the kids that at Thanksgiving. Likewise, when Stalin and Mao collectivized their farms, their people nearly starved to death.
High school teacher Tori Haidinger runs an experiment to show her students that this is just the way people act.
Each group of students gets a covered beaker of candies they must share. She tells the kids, take as many as you want and then pass them on to the next kid. Any left over will reproduce, just like fish, because the teacher will double them. What happens?
The beakers were emptied completely, because nobody shared. Bad news if the candies were fish.
Economists call this the "Tragedy of the Commons."
When Haidinger changed the rules and gave each student, rather than a group of students, his or her own private beaker, things worked out better.
She's privatizating the beakers. People sneer at the term privatization, but this time no one overfishes. Kids are careful to leave enough in their ponds and new generations of chocolate candies are born.
One of the students understands the lesson. "If it's ours, we will care more about it," she said.
The same principle is saving elephants in Africa. In many African countries, the elephants belong to everyone. Governments have outlawed killing them, but the vast plains are too big to police. So greedy poachers kill elephants and steal their tusks.
Roberts said, "It's a nice idea to say it's wrong to kill elephants. But that method has not worked."
In Zambia, Uganda and Kenya, where elephant hunting is banned, the number of elephants has actually dropped dramatically -- from 180,000 to 44,000 -- in the past four decades.
But in Zimbabwe, South Africa, Namibia and Botswana, local villagers have a form of ownership rights. They have the right to sell hunting licenses for about $10,000 per elephant.
And this permission to kill elephants is actually saving elephants.
"Oh, it's disgusting. But it works," Roberts said.
It works, because the villagers now say, these are our elephants. Even a former poacher now works to protect the elephants.
"The villagers have a profit motive to make sure that elephants don't get poached and killed. As a result, they take care of them. They don't want to kill the goose that lays the golden eggs," Roberts explained.
In these countries where villagers virtually own the elephants, elephant numbers have almost tripled -- from 80,000 in 1960 to about 230,000 in 2000.
So while sharing may feel warm and fuzzy, it often makes things worse.
By contrast, private ownership -- whether it's public toilets or hunting and fishing licenses -- makes the world better.
This story was originally reported Jan. 28, 2005.