Is it ever immoral to develop or promote technology that causes people to lose jobs by making human workers obsolete?

This is a very tough question!

I think that it can be and you are raising a concern that is highly important today. In the USA technology (along with subsidies) has permitted farmers to produce far more goods and cheaper prices than some farmers in under developed nations. Persons in Africa are not able to produce as much corn or cotton as an American farmer and they therefore cannot compete as well in international markets. In some cases, the hardship that this causes African farmers can be quite severe. You asked about morality, not legality. It may (or may not) violate any international law for American farmers to out-compete African farmers, but cases are easily imagined in which American self-restraint or assistance in terms of exporting efficient technology to African farmers may be a more respectful course of action.

Historically, there are a significant number of cases within a society when new technology has made many workers redundant. Some advocates of a free market system conclude that this is the inevitable pain that occurs in the course of the evolution of an economy. But I suggest that the hardship caused in such a blow to the work force might be important to minimize in a just state: for example, a manufacturer who has deployed technology leading to the loss of, say, a thousand workers may have some duty to insure that the workers have access to training that would enable them to find other forms of work.

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