When Kazuo Inamori was appointed to lead the restructuring of Japan Airlines (JAL) two years ago, analysts worried about his lack of experience in aviation. Never mind that he was about to turn 78, had founded two of Japan’s best-known companies – Kyocera, in electronics components, and KDDI, in telecoms – and was, for good measure, an ordained Buddhist priest. Studying Buddhist teachings, he told the Wall Street Journal four months into his new role, “improves the quality of my heart and mind and enriches myself as a human being. This enhanced spirit is useful when it comes to revitalising JAL”.

Priestly vocation is not a normal requirement for high corporate office, but the story illustrates the shallowness of the knee-jerk accusation that new executives lack sector experience. Virtually from the moment Scott Thompson of PayPal was selected to take the helm at Yahoo last week, analysts and commentators started picking at the online media and advertising holes in his curriculum vitae, despite Yahoo’s stressing his “deep industry experience”. In one sense, shareholders’ nervousness is understandable: Yahoo is in a hole and the last person appointed to pull it out – Mr Thompson’s ill-starred predecessor Carol Bartz – was also an outsider with no background in the consumer internet and online advertising business.

Gambling on a greenhorn to run a multinational clearly makes no sense. Also, in some, often regulated, sectors, domain knowledge is indispensable. Banking is the most obvious. Even seasoned executives Bob Diamond, at Barclays, and Brian Moynihan, at Bank of America, had to allay concerns that, as new chief executives of universal banks, they lacked experience in retail banking.