The historical experience with agriculture is, in fact, an excellent illustration of the so-called “Luddite fallacy.” This is the idea—and I think it is generally accepted by economists—that technological progress will never lead to massive, long-term unemployment.
The reasoning behind the Luddite fallacy goes roughly like this: As labor-saving technologies improve, some workers lose their jobs in the short run, but production also becomes more efficient. That leads to lower prices for the goods and services produced, and that, in turn, leaves consumers with more money to spend on other things. When they do so, demand increases across nearly all industries—and that means more jobs. That seems to be exactly what happened with agriculture: food prices fell as efficiency increased, and then consumers went out and spent their extra money elsewhere, driving increased employment in the manufacturing and service sectors.
Martin Ford, via Free exchange | Economist.com