The econ101 answer is that entities are always trying to negotiate a better deal for themselves. If we look at the entire population in aggregate, that means either a higher proportion of people in the workforce, or the people in the workforce increasing their output (usually through number of hours worked), or the firms acting to increase their constituents' share of the pie.

The way orthodox economists summarize this is that "there are 3 conflicting goals of monetary policy: full employment, full productivity, and stable prices". Any two of these preclude the third. Even the liberals admit that the system is unstable at its core.

This is something that is supplemented by LTV, and you can really see where the deal goes sour by having a currency that's set by market forces, instead of by something more constant and objective.