Mergers and acquisitions (M&A) are major events in organizational development and the post-merger phase is widely recognised as being crucial for value creation. One of the most important decisions in this process is the speed of integration. However, despite a growing body of literature on this subject, conclusions remain a source of persistent equivocality. In fact, this debate has been dominated by diametrically opposed, and often highly normative, views advocating either fast or slow post-merger integration (PMI). One commonality within this discussion though, is the shared assumption that integration proceeds at a linear, constant rate, whatever the speed. We challenge this assumption.

We undertook a 30-month, longitudinal study of two merging, not-for-profit, organisations. Using detailed and multiple sources of process data, we were able to identify and track periods of comparatively rapid and equally comparatively slower integration during the two-and-a-half- year PMI process. We thus offer a novel empirical demonstration of the changes in speed during the PMI process. We support this with a theoretical discussion using the temporal concepts of chronos and kairos. We analyse the determinants and mechanisms of changes in speed, asking why and how these variations occur. We call this mechanism the kairotic switch and discuss its theoretical and managerial uses and implications.