A recent article in the Wall Street Journal (subscription required) says that executives who don’t conduct thorough “human due diligence” before completing an acquisition can suffer “steep long-term attrition.”

One featured researcher says that in a recent study, he found targeted companies lose close to 21% of their managers each year, more than double the turnover experienced in non-merged firms, for at least 10 years after an acquisition. The article goes on to say that though no two companies manage employees and operations in exactly the same way, the more their decision-making styles and value overlap, the more they will benefit from the merger. …