Correct. Also most jobs are only worth something as part of a unit. A janitor alone is useless, but a janitor part of an office environment is extremely valuable to allow everyone else to work.
An hour of labor is an hour of labor. Productivity can increase or decrease, but the labor will still be an hour. A chair that is able to be built in half the time it once was due to new tools and methods has less Value than it once had.
Correct. Also most jobs are only worth something as part of a unit. A janitor alone is useless, but a janitor part of an office environment is extremely valuable to allow everyone else to work.
An hour of labor is an hour of labor. Productivity can increase or decrease, but the labor will still be an hour. A chair that is able to be built in half the time it once was due to new tools and methods has less Value than it once had.
Read Wage Labor and Capital and follow it with Value, Price and Profit if you want to really understand what Marxists believe. They go in-depth on what constitutes Value by Labor.