“A standard economists’ argument goes roughly like this: Technology is introduced only when it is profitable, and lowers the costs of production. Thus the prices of the goods and services produced must go down, leaving consumers with more money to spend on other products, and this creates demand for any workers who are displaced. Thus there will always be new industries growing up to employ any workers displaced by technological change in existing industries. But that argument applies just as well to the oats, apples, and grooming needed for horses to subsist as for the wages of humans, no? One could conclude that there will always be things for horses to do that will have them create enough value to earn their keep.”