New Zealand bank mergers and efficiency gains

This paper uses accounting ratios and DEA (Data Envelopment Analysis) to explore the efficiency impacts of 6 bank mergers in New Zealand between 1989 and 1998. The paper is the first reported application of DEA to the New Zealand banking sector, and its methodology is based around that used by Avkiran in his study published in the Journal of Banking and Finance in 1999. Consistent with earlier research, acquiring banks were found to be generally larger than their targets, although they were not consistently more efficient. In a majority of cases the merger led to an increase in efficiency, consistent with a trend observed for the banking sector as a whole. No clear conclusions could be drawn on possible public benefits from the mergers.