Extending research on the performance of Mergers and
Acquisitions (M&As), this paper seeks to explain how the
post-acquisition integration phase affects acquisition performance.
Despite extensive research efforts, there remains a scant understanding
of how acquisition implementation, particularly in the post-acquisition
integration phase, impacts the performance of M&As. Based on an
extensive study of eight acquisitions, in this paper, a grounded model
detailing the mechanisms by which the post-acquisition integration phase
affects acquisition performance is developed. The model posits that
integration-related factors do not bear directly upon acquisition
performance. Instead, their effect is mediated by functional
organizations in both firms. When focusing into these functional
mediating dynamics, we observe that integration-related processual,
behavioral and cultural factors affect the identified functional
mediators in different ways. Going forward, we echo calls for integrated
perspectives to the study of M&A and M&A performance in
particular.