Recent financial history shows that “invisible” structural conditions, such as the law of compound interest, widespread acceptance of new forms of electronic money, preferences for offshore finance, faith in the U.S. dollar, etc., all have important consequences for wealth formation, destruction, and transfer. In the human ecology framework of Chapter 1, these intangible “belief systems” and “social agreements,” through the institutions of finance, mutually impact the tangible “human populations” and their “physical environments and resources” through new channels.