Section Five
The statistical models, which employed a comprehensive
set of control variables, analyzed labor productivity as
measured by the number of hours involved in manufacturing a
vehicle. They also analyzed quality as measured by the number
of defects reported by consumers. Manufacturing also provides
a good source of data because it is possible to obtain objective
measures of productivity. The study found that the system of
high-performance human resource practices was associated
with greater productivity and quality. Furthermore, the index
for the system of human resource practices had greater
explanatory power for productivity and quality than the
individual practices by themselves.^117
Overall, the evidence strongly supports the
hypothesis that assembly plants using flexible
production systems, which bundle human
resource practices into a system that is integrated
with production/business strategy, outperform
plants using more traditional mass production
systems in both productivity and quality. These
results provide the strongest statistical evidence
to date of a positive relationship between
innovative human resource practices and
economic performance...^118