because added value serves at compensating firms’ personnel costs, VA/E is considered
to be a mediator between vertical alignment and PC/VA. In similar circumstances, there
exists a strong relationship between PC/VA and VA/E. The average personnel cost per
employee however is significantly higher (+12.13%) for advanced than for bottom-up
moderate planners. This explains why, in comparison with moderate planners, advanced
planners in terms of VA/E seem to benefit from combining both vertical alignment
modes, but not in terms of PC/VA. Consequently, assuming a strong relationship between
pay, staff qualifications and employee value for the firm, one could attribute the average
productivity effect of advanced planners to their staff qualifications instead of their
vertical alignment efforts. However, the results are robust to the inclusion of personnel
cost per employee as control variable in the ANCOVA model.