We don’t really know why the U.S. banking industry is consolidating rapidly, as it has been doing for the last decade or so. After a large number of studies on the topic including this one, what seems clear is that consolidation is not producing significant efficiencies — at least not on average. Other dimensions of the consolidation trend — such as its heavy concentration in large banks — are just as poorly understood. Given this ignorance as to the “why” of consolidation, it is extremely risky to predict its future effects. Based on past experience and data, at least, we can conclude the following.