It's substantively different. The level of compensation you could expect from copyright needs to be high enough that creators/inventors in general feel that it

It's substantively different. The level of compensation you could expect from copyright needs to be high enough that creators/inventors in general feel that it may be worthwhile to create/invent stuff. That level of compensation may be exactly enough to pay for a musician to make a track. We know this is not the case, it's more like a lottery ticket; some musicians make millions (much more than would be needed to entice them to choose this line of work) and many make almost nothing, but still persist. If you relax copyright provisions so that average compensation is halved, this would presumably have a non-linear impact. Maybe a 50% decrease in expected compensation only results in -10% new works. Maybe in -80%. For example, it is completely implausible that retroactively extending copyright (as has been done) results in any additional works being created at all - just higher profits for existing owners. This also applies to the costs; a higher cost of production (e.g. cost of living) doesn't necessarily need to lead to more stringent copyright restraints, nor lower costs to more lax restrictions.