Deals without delusions

Pursuing a merger or acquisition is inherently difficult. Things get even harder when executives are blind to their own faulty assumptions, say Lovallo--a professor at the University of Western Australia Business School and a senior adviser to McKinsey--and three of his McKinsey colleagues. The authors identify biases that can surface at each step of the M&A process and provide practical tips for rising above them--an approach they call targeted debiasing. During the preliminary due-diligence stage, biases abound. To overcome the confirmation bias, aggressively seek evidence that challenges your initial hypothesis about a deal. The best medicine for overconfidence in identifying revenue and cost synergies is to learn from precedents at your firm and others. Avoiding underestimation of cultural differences between your company and the target requires understanding the differences in the ways people interact at each organization. Misjudging the time and resources you need is at the core of the planning fallacy, which you can elude by formally identifying best practices and continually revisiting them. Finally, dilute conflict of interest by soliciting dispassionate external expertise. The bidding phase is vulnerable to the winner's curse, a phenomenon common in auctions. To avoid paying too much for a target, actively generate alternatives to the deal under consideration and develop a set of bidding cutoff rules. After offering an initial bid, deal makers are susceptible to anchoring, whereby they remain attached to their original price estimate, and to the sunk cost fallacy that they've invested too much to stop now. The secret to overcoming both: Use your newly available access to the target's books to better assess the investment case--and change your tune accordingly.