Statistical studies over the last forty-five years show that, although there are success stories, very many mergers and acquisitions do not result in the increased operating profits that economics textbooks would lead one to expect. As consultancy McKinsey have put it, ‘Anyone who has researched merger success rates knows that roughly 70% fail’. Yet—mysteriously—M&A activity has boomed across the globe, with a forty-fold increase in deals done each year now compared with four decades ago, ...

Spending on M&A has, in aggregate, grown so fast that it has even overtaken capital expenditure on increasing and maintaining physical assets. Yet McKinsey, the leading management consultancy, reports that "Anyone who has researched merger success rates knows that roughly 70% fail". The idea that businesses might be using huge and increasing sums of shareholders’ money for an activity that more often than not leads to failure calls into question the information on which M&A decisions are b...