I am increasingly convinced that the low "productivity" (defined as euros of output per euro of wages or hour of work) is the result of chronic underinvestment in physical plant.

Low wages are an inefficient subsidy to management because they discourage investment needed to make best use of employee's working hours. Think of a fast food restaurant.  If wages are high, things become automated.  For example instead of having a fryer manned by a low wage worker, you have machines that only need to be loaded and unloaded. Same thing with filling drinks. But these things cost money. Labor saving devices only make business sense if their purchase and upkeep costs less than paying someone to do it manually.  

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg