The pessimistic argument is as follows: If machines costing $5 an hour can produce the same amount as workers costing $10 an hour, employers have an incentive to substitute machines for labor up to the point that the costs are equal – that is, when the wages of the workers have fallen to $5 an hour. As machines become ever more productive, so wages tend to fall even more, toward zero, and the population becomes redundant.
悲观论是这样的：如果机器能以每小时5美元的成本生产和成本每小时10美元的工人同样多的产品，厂商就有激励用机器代替人力，直到两者的成本相等为止——也就是说，直到工人工资降到每小时5美元为止。随着机器生产率的不断提高，工资将不断下降，趋近于零，人口就会变得过剩。