It is instructive to consider robots in this context. They replace local human workers like immigrants, but unlike immigrants, they do not have the same demand profile as humans. In return for their work, they ask for energy, machinery and engineering. This type of demand undoubtedly creates fewer jobs for humans compared to an immigrant worker. So, when it comes to the health of the economy, you should fear robots much more than immigrants.
According to my beginner understanding of econ, this part seems wrong. In aggregate, a household or country will benefit more from a robot which cleans floors at the expense of a little electricity, than from an extra person who does the same job but also requires room and board.
It depends on how you look at it. In terms of productivity (output per labour cost), more robots is better. But if all cleaning staff is replaced by robots, the robot manufacturer profits while the displaced workers have less disposable income, thus there is less demand for the local economy (local groceries store, gas station, hairdresser, realor etc.), which suffers as a consequence.
According to my beginner understanding of econ, this part seems wrong. In aggregate, a household or country will benefit more from a robot which cleans floors at the expense of a little electricity, than from an extra person who does the same job but also requires room and board.
It depends on how you look at it. In terms of productivity (output per labour cost), more robots is better. But if all cleaning staff is replaced by robots, the robot manufacturer profits while the displaced workers have less disposable income, thus there is less demand for the local economy (local groceries store, gas station, hairdresser, realor etc.), which suffers as a consequence.