The question of whether or not mergers and acquisitions have helped to enhance banks' efficiency and profitability has not yet been conclusively resolved in the literature. We argue that this is partly due to the severe methodological problems involved. In this study, we analyze the effect of German bank mergers in the period 1995-2000 on banks' profitability and cost efficiency. We suggest a new matching strategy to control for the selection effects arising from the fact that predominantly under-performing banks engage in mergers. Our results indicate a neutral effect of mergers on profitability and a positive effect on cost efficiency. Comparing our results with those obtained from a naive performance comparison of merging and non-merging banks indicates a severe negative selection bias with regard to the former.Keywords: Bank mergers, performance measurement, propensity score matching JEL classification: G21, G34
Non-technical summaryIn the past banks have often met challenges arising from higher cost pressure often by engaging in mergers and acquisitions in order to enhance their long-term profitability.Given that banks have tried to achieve economies of scale it is very surprising that a number of empirical studies have found that mergers and acquisitions do not improve the merging banks' performance. In this paper we critically reassess this seeming paradox.In our view, it is doubtful whether the success of M&As can by assessed by directly comparing merged with non-merging banks as some of these studies have done. In doing so, they neglect the fact that merging banks often represent an under-performing sample.If this is indeed the case, it is hardly surprising that the merged banks exhibit a relatively low profitability. In order to answer the question of whether M&As have helped to increase banks' profitability, one should therefore rather compare merging banks with non-merging banks that had been in a similar position. In this paper, we propose a matching strategy, similar to those deployed in clinical studies that evaluate the success of a particular treatment. Our matching approach for merging banks is carried out in two steps. As a first step, we use balance sheet and merger data to estimate the probability that a particular bank will engage in a merger in the following year. Different models are estimated for acquiring banks and targets. As a second step, we select for each acquiring bank and for each target a corresponding control bank from the set of non-merging banks, which minimizes the distance between the ex ante merging probabilities. These control banks now form a suitable benchmark for assessing the performance of the merger banks in our sample. Our results can be summarized as follows:1. The merging banks were indeed unsuccessful in improving their profitability, which is probably due to the restructuring costs these banks incurred.2. Nevertheless, these banks were able to improve their cost efficiency, which may help the banks to improve their long-term profitability.3. All in all,...