What separates the co-CEOs that work from those that don’t?

David Ellison’s appointment of Ynon Kreiz as co-CEO of the merging Paramount Skydance and Warner Bros. Discovery empire is a timely reminder: the lone chief-executive model isn’t the only way to run a company. Rather, in an environment characterized by complexity, speed and pressure, sharing the CEO role can be a strength that delivers increased shareholder returns. Analysis from Harvard Business Review supports this, finding that companies with two CEOs delivered an average sharehol...