When Expedia’s chief executive Mark Okerstrom stepped aside over strategic disagreements in December, it came after just two years in charge. By leaving after such a brief spell at the top he joined a significant leadership trend: the US beats both the UK and Europe in speed of CEO turnover. According to new research, US companies are more likely to change their lead executives in under three years than companies in Europe and the UK. The research, from shareholder advisory firm SquareWell Partners, reveals that 28% of US corporate leaders parted company with their employers in three years or less. European companies are more likel