Does ISO 9000 certification matter for firm performance? A group analysis of Greek listed companies

In this study we investigate the performance dynamics of the ISO 9000 certification for varying time-frames and firm groupings by initiating a new dimension related to admission in the stock exchange market. We distinguish certified firms into two subgroups: the firms that adopted the certification before getting listed and those that adopted while being listed. The empirical results indicate that, in both cases, the ISO 9000 certification is associated with higher financial performance for adopting firms in comparison to the control group comprising non-certified firms. Higher operating performance versus the non-certified peers in terms of inventory turnover ratio was also found among high and low technology prototype certified manufacturing firms. Furthermore, the evidence suggests that the impact of the certification in terms of duration is higher for the group of firms initializing the certification after getting listed. Additionally, the robustness analysis indicates that the upgraded 2000 and 2008 versions of the ISO 9000 standard have consistently impacted in a significant way on firm performance. These results provide useful insights to managers, investors and regulators regarding the time decision for implementing the first ISO 9000 certification, the continuation of certification and its impact on the performance of adopting firms.