“Evidence based” is both a powerful management tool, enabling us to adopt a scientific approach to decision making, and of course it’s a “get out of jail free” card. If what we do is evidence based, and it goes wrong, it’s not our fault, is it?
“Evidence based” is not a tool available to leaders. Whilst they can assemble the best data they can, it will always be incomplete. Leaders work on probabilities and there will be no evidence, other than after the event, to analyse their decision.
It’s why leadership is difficult. Managers get umbrellas, but leaders can never be sure when or where it’s going to rain. They can get forecasts, but they never know. Management is safe, leadership is not.
Leadership is not a reward, it’s a privilege accorded to those who can get people to dance in the rain with them.