Previous literature has suggested both positive and negative effects of age diversity on labor productivity: positive because of the potential knowledge complementarities between employees of different ages and negative because of the age-related value differences that might reduce cohesion and cooperation, hampering firm performance. Using a Belgian sample of 5892 organizational observations (2008-2011), we unraveled these countervailing effects in two ways. First, we built on prior studies to suggest that the effect of age diversity depends on the particular shape of the age distribution: positive when it is heterogeneous (i.e., variety) and negative when it is polarized (i.e., polarization). This was supported by our findings. Second, we explored the moderating impact of two contextual contingencies, firm size and job security. As expected, the positive effect of age variety is reinforced in large firms and in firms where job security is high. Although firm size also emphasizes the negative effect of age polarization on productivity, job security, unexpectedly, does not moderate this relationship. Our study offers a valuable contribution to the literature as it reveals the boundary conditions of the competing implications of age diversity and, thus, allows one to account for the inconclusive findings reported in previous literature.

As employees are among firms’ most important resources and labor markets are facing serious labor shortages, firm-level collective turnover is one of the most important challenges facing organizations. Context-emergent turnover theory provides a theoretical framework for the performance implications of collective turnover and argues that context, and in particular, firm size, plays a crucial role in the collective turnover–performance relationship. Yet, the moderating role of firm size remains undertheorized, empirically understudied, and thus, unclear. Based on the resource-based view of the firm, we develop a theoretical framework for two competing perspectives (a negative and a positive one) on the role of firm size and put forward the firm’s knowledge intensity as a crucial additional moderator. The main premise is that whereas firm size determines what resources firms have to successfully cope with turnover, knowledge intensity determines the resources firms need to do so. We propose a three-way interaction, suggesting that firm size reinforces the harmful effect of turnover in highly knowledge-intensive firms and buffers it in firms with low levels of knowledge intensity. Using a unique multi-industry and longitudinal administrative data set of 6,913 Belgian firms (2012–2016), we find support for these assumptions. This study highlights the importance of the context in which firms have to deal with turnover, and it spurs researchers to go beyond studying turnover in narrow study contexts, to take into account the interplay among different but intertwined organizational contingencies, and to acknowledge both the quantitative (how many employees leave) and qualitative components (who leaves) of turnover.

Age heterogeneity in Western workforces is increasing, generating potential informational benefits as well as harmful age-based social categorizations. When can firms benefit from age heterogeneity? Building on the categorization-elaboration model, we propose the average age distance between employees as a fundamental contingency. Using a longitudinal archival sample of 3,336 Belgian firms (2012)(2013)(2014)(2015), we find that firms with a high level of age heterogeneity are less productive when employees' average distance is great (Study 1). Through an online experiment with 260 US participants, we show that employees in age-heterogeneous workforces are less willing to engage in inter-age cooperative contact and knowledge exchange under a great level of average age distance (Study 2). Our findings support that great distances foster age-based social categorizations that undermine the productive information elaborations between employees of different ages. This broadens our knowledge on the implications of workforce age diversity and helps organizations understand when they can(not) reap the productivity benefits of their age-diverse workforce. Moreover, this study's theory and implications are relevant to other types of diversity for which both heterogeneity and distance are meaningful constructs.We also discuss the practical implications of this study.

The aging population implies a wider age range within a workforce, increasing the risk of age diversity as separation (the clustering into age‐based subgroups), which is considered a turnover stimulator. We provide a new theoretical perspective to age diversity and turnover research, arguing that age separation may not only increase turnover through perceived age discrimination (i.e., a self‐categorization perspective), but can also reduce it through increased perceived belongingness (i.e., a social identity perspective). Following the idea of asymmetric diversity effects, we propose the workforce's average age as a crucial moderator. A longitudinal sample of 2,393 Belgian organizations (2012–2015) reveals that firm‐level age separation stimulates firm‐level collective voluntary turnover, but only in firms with an older average age (Study 1). Data from a representative sample of 4,764 employees from six European countries are consistent with the idea that perceived age separation stimulates aging workers’ turnover intention through increased perceived discrimination and reduced belongingness, and reduces younger workers’ turnover intention through increased belongingness (Study 2). These findings support that age diversity conceptualized as separation is not as unmistakably detrimental for turnover as previously assumed and affects younger and older employees and workforces differently. From a practical perspective, understanding the role of age in the age separation–turnover relationship may help organizations to prevent the loss of valuable knowledge through the departure of both older and younger employees.