Dekker, R.

product innovation product sales flexibility labor market model employee performance variable knowledge contract impact personnel management sample labor markets level innovation performance kleinknecht table survey sector evidence people worker share industry equation labor turnover export economic labour percentage training research intensity process netherland result output r &d intensity productivity growth coefficient relation paper turnover study firm-level university control sample selection bias labor relations heckman model number journal firm size report database observation 0.01 heckman resource commitment indicator sme sample fixed-term contracts osa database market leaders control variables estimate selection fluctuation arvaniti series firm-level data t-value job rotation investment