Andrew K asked (repeatedly) in [OPE-L:3579]:
> Do capitalists always have an incentive, irrespective of the wage rate, to
> substitute machines for workers, because the additional machine costs
> per unit of output can be less than the repression costs saved per unit
> of output?
The answer to the above question is -- no.
Capitalists do not _always_ have an incentive to substitute machinery for
workers since, as you say, the additional machine costs per unit of output
_can_ (but _may not_) be less than the "repression costs" saved per unit
of output.
There is certainly no reason to believe that the introduction of more
machinery will _necessarily_ mean that the [possible] additional surplus
value caused by a [possible] increase in the intensity of work will
by itself justify the expenditure on additional machinery.
As for the larger question of _why_ the machinery is introduced in
practice, this is an empirical matter that is worthy of investigation but
would be difficult to get accurate information on. There certainly have
been some empirical studies, e.g. questionaires to capitalists asking them
to rank the possible reasons for why they have or might consider
purchasing a new technology (I am familiar with some studies of this sort
regarding the diffusion of industrial robotics). Capitalist firms would
certainly consider the likely consequences of new technology on the
intensity of work, but I have seen very little evidence that it is in
practice a _primary_ factor that motivates capitalists' investment
decisions in new technology.
In Solidarity,
Jerry