Friday, September 12, 2014

The Endangered Species Act and the Double Coincidence of Wants

By Peter Klein

This year’s silly Copenhagen Zoo controversy reminded us that, when it comes to animal care, people have difficulty thinking clearly. NPR’s Planet Money ran an interesting piece this morning about animal barter among zoos. The US Endangered Species Act and  global treaties such as the Convention on International Trade of Endangered Species of Wild Fauna and Flora make it a crime to buy and sell zoo animals like other commodities. This makes it difficult for zoos not only to obtain new animals, but also to get rid of existing, unwanted ones. (Hence the fate of poor Marius the giraffe.)

To get around these rules, zoos have adopted a complex and cumbersome barter system. Zoos are, under the law, allowed to make animal-for-animal swaps. But, as economists such as Carl Menger explained more than a century ago, barter is hampered by the double coincidence of wants: to trade with you, it’s not enough that I want what you have; you also have to want what I have. Money eliminates the double coincidence of wants by introducing a third commodity that serves as a generally accepted medium of exchange. Unfortunately for the zoos, money is off the table. And hence:

The New England Aquarium in Boston was recently in the market for some lookdown fish, and they knew of an aquarium in North Carolina that was willing to trade some.

The folks in North Carolina wanted jellyfish and snipe fish. The New England aquarium had plenty of jellyfish — but no snipe fish.

Steve Bailey, the curator of fish at the New England Aquarium, wound up making a deal to get snipe fish from an aquarium in Japan, in exchange for lumpfish. Then he sent the snipe fish and some jellyfish to North Carolina. In exchange, he finally got his lookdown fish.

Allowing zoos to buy and sell animals using money, rather than complex and inefficient barter arrangements — why, that’s inhumane!

The above originally appeared at


  1. Ripe for entrepreneurship. Some body makes a BitAnimal system where animals (or fractions of animals) between countries can be more conveniently handled. Seriously.

    In a world where all of these animals (worldwide) were protected by property rights, zoos would be the most humane and happy world for wild animals. Instead they are a preview of what life looks like when you are "owned" by the government.

  2. Didn't you know, money is the root of all evil!!! And it's too efficient to suit the bureaucratic mind.
    Besides, how could these people find meaning in life if all peaceful, voluntary interactions were legal.