4. Discussion
Previous research provides unstable evidence about the existence of synergistic effects among the components of HRM systems (e.g. Chadwick, 2010). Following several calls in recent HRM literature (e.g. Boxall, 2013; Posthuma et al., 2013), our study sought to test whether the AMO components of HRM systems targeting organizational ethics present independent or synergistic effects on two key outcomes, i.e. the employee perception of benevolent and principled ethical climates. Our study provides robust and large scale evidence of synergistic effects among the AMO policy domains in HRM systems targeting organizational ethics. Specifically, three (out of six) interactions have proven significant in terms of fit and magnitude of effects for benevolent and principled ethical climates. Earlier synergistic claims (e.g. Jiang et al., 2012), thus, can be transferred only partially to the so-far unexplored outcome of ethical climates.